# SPDX-FileCopyrightText: 2019 ash contributors # # SPDX-License-Identifier: MIT defmodule Ash.Query do @moduledoc """ A data structure for reading data from a resource. Queries are run by calling `Ash.read/2`. Examples: ```elixir require Ash.Query MyApp.Post |> Ash.Query.filter(likes > 10) |> Ash.Query.sort([:title]) |> Ash.read!() MyApp.Author |> Ash.Query.aggregate(:published_post_count, :count, :posts, query: [filter: [published: true]]) |> Ash.Query.sort(published_post_count: :desc) |> Ash.Query.limit(10) |> Ash.read!() MyApp.Author |> Ash.Query.load([:post_count, :comment_count]) |> Ash.Query.load(posts: [:comments]) |> Ash.read!() ``` To see more examples of what you can do with `Ash.Query` and read actions in general, see the [writing queries how-to guide](/documentation/how-to/write-queries.livemd). ## Capabilities & Limitations Ash Framework provides a comprehensive suite of querying tools designed to address common application development needs. While powerful and flexible, these tools are focused on domain-driven design rather than serving as a general-purpose ORM. Ash's query tools support: - Filtering records based on complex conditions - Sorting results using single or multiple criteria - Setting result limits and offsets - Pagination, with offset/limit and keysets - Selecting distinct records to eliminate duplicates - Computing dynamic properties at query time - Aggregating data from related resources While Ash's query tools often eliminate the need for direct database queries, Ash is not itself designed to be a comprehensive ORM or database query builder. For specialized querying needs that fall outside Ash's standard capabilities, the framework provides escape hatches. These mechanisms allow developers to implement custom query logic when necessary. ### Important Considerations 1. Ash is primarily a domain modeling framework, not a database abstraction layer 2. While comprehensive, the tooling is intentionally constrained to resource-oriented access 3. Escape hatches exist for cases that require custom query logic For complex queries that fall outside these tools, consider whether they represent domain concepts that could be modeled differently, or if they truly require custom implementation through escape hatches. ## Escape Hatches Many of the tools in `Ash.Query` are surprisingly deep and capable, covering everything you need to build your domain logic. With that said, these tools are *not* designed to encompass *every kind of query* that you could possibly want to write over your data. `Ash` is *not* an ORM or a database query tool, despite the fact that its query building tools often make those kinds of tools unnecessary in all but the rarest of cases. Not every kind of query that you could ever wish to write can be expressed with Ash.Query. Elixir has a best-in-class library for working directly with databases, called [Ecto](https://hexdocs.pm/ecto/Ecto.html), and if you end up building a certain type of feature like analytics or reporting dashboards, you may find yourself working directly with Ecto. Data layers like AshPostgres are built on top of Ecto. In fact, every `Ash.Resource` is an `Ecto.Schema`! > ### Choose escape hatches wisely {: .warning} > > You should choose to use Ash builtin functionality wherever possible. > Barring that, you should choose the *least powerful* escape hatch that > can solve your problem. The options below are presented in the order > that you should prefer them, but you should only use *any of them* > if no builtin tooling will suffice. ### Fragments Fragments only barely count as an escape hatch. You will often find yourself wanting to use a function or operator specific to your data layer, and fragments are purpose built to this end. You can use data-layer-specific expressions in your expressions for filters, calculations, etc. For example: ```elixir Resource |> Ash.Query.filter(expr(fragment("lower(?)", name) == "fred")) |> Ash.Query.filter(expr(fragment("? @> ?", tags, ["important"]))) ``` ### Manual Read Actions See [the manual read actions guide](/documentation/topics/actions/manual-actions.md). ### `d:Ash.Resource.Dsl|actions.read.modify_query` When running read actions, you can modify the underlying data layer query directly, which can solve for cases when you cannot express your query using the standard Ash query interface. ```elixir actions do read :complex_search do argument modify_query {SearchMod, :modify, []} end end ``` ```elixir defmodule SearchMod do def modify(ash_query, data_layer_query) do # Here you can modify the underlying data layer query directly # For example, with AshPostgres you get access to the Ecto query {:ok, Ecto.Query.where(data_layer_query, [p], fragment("? @@ plainto_tsquery(?)", p.search_vector, ^ash_query.arguments.search_text))} end end ``` ### Using Ecto directly For data layers like `AshPostgres`, you can interact directly with `Ecto`. You can do this by using the `Ash.Resource` as its corresponding `Ecto.Schema`, like so: ```elixir import Ecto.Query query = from p in MyApp.Post, where: p.likes > 100, select: p MyApp.Repo.all(query) ``` Or you can build an `Ash.Query`, and get the corresponding ecto query: ```elixir MyApp.Post |> Ash.Query.for_read(:read) |> Ash.data_layer_query() |> case do {:ok, %{query: ecto_query}} -> ecto_query |> Ecto.Query.where([p], p.likes > 100) |> MyApp.Repo.all() {:error, error} -> {:error, error} end ``` """ defstruct [ :__validated_for_action__, :action, :domain, :distinct, :filter, :resource, :tenant, :timeout, :lock, :to_tenant, sort_input_indices: [], before_transaction: [], after_transaction: [], around_transaction: [], invalid_keys: MapSet.new(), load_through: %{}, action_failed?: false, combination_of: [], after_action: [], authorize_results: [], aggregates: %{}, arguments: %{}, before_action: [], calculations: %{}, context: %{}, errors: [], limit: nil, load: [], offset: 0, page: nil, params: %{}, phase: :preparing, select: nil, sort: [], distinct_sort: [], valid?: true ] @typedoc """ A query struct for reading data from a resource. Contains all the configuration needed to read data including filters, sorting, pagination, field selection, and relationship loading. Built incrementally through functions like `filter/2`, `sort/2`, `load/2`, etc. """ @type t :: %__MODULE__{ __validated_for_action__: atom | nil, action: Ash.Resource.Actions.Read.t() | nil, domain: module | nil, distinct: [atom], filter: Ash.Filter.t() | nil, resource: module, tenant: term(), combination_of: [Ash.Query.Combination.t()], timeout: pos_integer() | nil, action_failed?: boolean, after_action: [ (t, [Ash.Resource.record()] -> {:ok, [Ash.Resource.record()]} | {:ok, [Ash.Resource.record()], [Ash.Notifier.Notification.t()]} | {:error, any}) ], authorize_results: [ (t, [Ash.Resource.record()] -> {:ok, [Ash.Resource.record()]} | {:error, any}) ], aggregates: %{optional(atom) => Ash.Filter.t()}, arguments: %{optional(atom) => any}, before_action: [(t -> t)], before_transaction: [before_transaction_fun], after_transaction: [after_transaction_fun], around_transaction: [around_transaction_fun], calculations: %{optional(atom) => :wat}, context: map, errors: [Ash.Error.t()], limit: nil | non_neg_integer(), load: keyword(keyword), offset: non_neg_integer(), page: keyword() | nil | false, params: %{optional(atom | binary) => any}, phase: :preparing | :before_action | :after_action | :executing, select: nil | [atom], sort: [atom | {atom, :asc | :desc}], valid?: boolean } @read_action_after_action_hooks_in_order? Application.compile_env( :ash, :read_action_after_action_hooks_in_order?, false ) @typedoc "Result type for around_transaction hooks, containing either successful records or an error." @type around_result :: {:ok, list(Ash.Resource.record())} | {:error, Ash.Error.t()} @typedoc "Function type for before_transaction hooks that run before query execution." @type before_transaction_fun :: (t -> t | {:error, any}) @typedoc "Function type for after_transaction hooks that run after query execution." @type after_transaction_fun :: (t, {:ok, list(Ash.Resource.record())} | {:error, any} -> {:ok, list(Ash.Resource.record())} | {:error, any}) @typedoc "Function type for around_transaction hooks that wrap query execution in a transaction." @type around_transaction_fun :: (t -> {:ok, Ash.Resource.record()} | {:error, any}) alias Ash.Actions.Sort alias Ash.Error.Invalid.TimeoutNotSupported alias Ash.Error.Load.NoSuchRelationship alias Ash.Error.Query.{ AggregatesNotSupported, InvalidArgument, InvalidCalculationArgument, InvalidLimit, InvalidOffset, InvalidPage, InvalidQuery, NoReadAction, ReadActionRequiresActor, Required } alias Ash.Query.{Aggregate, Calculation} require Ash.Tracer defimpl Inspect do import Inspect.Algebra def inspect(query, opts) do load_through_attributes = Map.to_list(query.load_through[:attributes] || %{}) query = %{ query | load: Keyword.merge(query.load || [], load_through_attributes), calculations: Map.new(query.calculations, fn {name, calc} -> if load_through = query.load_through[:calculations][name] do {name, {calc, load_through}} else {name, calc} end end) } query = %{ query | calculations: Ash.Actions.Read.Calculations.map_without_calc_deps(query.calculations) } sort? = query.sort != [] distinct_sort? = query.distinct_sort != [] load? = query.load != [] aggregates? = query.aggregates != %{} calculations? = query.calculations != %{} limit? = not is_nil(query.limit) offset? = not (is_nil(query.offset) || query.offset == 0) filter? = not is_nil(query.filter) errors? = not Enum.empty?(query.errors) tenant? = not is_nil(query.tenant) select? = query.select not in [[], nil] distinct? = query.distinct not in [[], nil] lock? = not is_nil(query.lock) page? = not is_nil(query.page) combination_of? = query.combination_of != [] container_doc( "#Ash.Query<", [ concat("resource: ", inspect(query.resource)), or_empty( concat("action: ", inspect(query.action && query.action.name)), not is_nil(query.action) ), or_empty(concat("tenant: ", to_doc(query.to_tenant, opts)), tenant?), arguments(query, opts), # TODO: inspect these specially or_empty( concat( "combination_of: ", to_doc(query.combination_of, %{opts | custom_options: [in_query?: true]}) ), combination_of? ), or_empty(concat("filter: ", to_doc(query.filter, opts)), filter?), or_empty(concat("sort: ", to_doc(query.sort, opts)), sort?), or_empty(concat("distinct_sort: ", to_doc(query.distinct_sort, opts)), distinct_sort?), or_empty(concat("limit: ", to_doc(query.limit, opts)), limit?), or_empty(concat("offset: ", to_doc(query.offset, opts)), offset?), or_empty(concat("load: ", to_doc(query.load, opts)), load?), or_empty(concat("aggregates: ", to_doc(query.aggregates, opts)), aggregates?), or_empty(concat("calculations: ", to_doc(query.calculations, opts)), calculations?), or_empty(concat("errors: ", to_doc(query.errors, opts)), errors?), or_empty(concat("select: ", to_doc(query.select, opts)), select?), or_empty(concat("distinct: ", to_doc(query.distinct, opts)), distinct?), or_empty(concat("lock: ", to_doc(query.lock, opts)), lock?), or_empty(concat("page: ", to_doc(query.page, opts)), page?) ], ">", opts, fn str, _ -> str end ) end defp arguments(query, opts) do if query.action do if is_nil(query.action) || Enum.empty?(query.action.arguments) do empty() else args = query.action.arguments |> Enum.reduce(%{}, fn argument, acc -> case Ash.Query.fetch_argument(query, argument.name) do {:ok, value} -> if argument.sensitive? do Map.put(acc, argument.name, "**redacted**") else Map.put(acc, argument.name, value) end :error -> acc end end) if args == %{} do empty() else concat(["arguments: ", to_doc(args, opts)]) end end else empty() end end defp or_empty(value, true), do: value defp or_empty(_, false), do: empty() end defmacrop maybe_already_validated_error!(query) do {function, _arity} = __CALLER__.function quote do query = unquote(query) if !is_atom(query) && query.__validated_for_action__ do {:current_stacktrace, stacktrace} = Process.info(self(), :current_stacktrace) require Logger Logger.warning(""" Query has already been validated for action #{inspect(query.__validated_for_action__)}. For safety, we prevent any changes after that point because they will bypass validations or other action logic. However, you should prefer a pattern like the below, which makes any custom modifications *before* calling the action. Resource |> Ash.Query.new() |> Ash.Query.#{unquote(function)}(...) |> Ash.Query.for_read(...) #{Exception.format_stacktrace(stacktrace)} """) end end end @doc """ Attach a filter statement to the query labelled as user input. Filters added as user input (or filters constructed with `Ash.Filter.parse_input`) will honor any field policies on resources by replacing any references to the field with `nil` in cases where the actor should not be able to see the given field. This function does not expect the expression style filter (because an external source could never reasonably provide that). Instead, use the keyword/map style syntax. For example: `expr(name == "fred")` could be any of - map syntax: `%{"name" => %{"eq" => "fred"}}` - keyword syntax: `[name: [eq: "fred"]]` See `Ash.Filter` for more. """ def filter_input(query, filter, opts \\ []) do query = new(query) case Ash.Filter.parse_input(query.resource, filter, opts) do {:ok, filter} -> do_filter(query, filter) {:error, error} -> add_error(query, :filter, error) end end @doc """ Produces a query that is the combination of multiple queries. All aspects of the parent query are applied to the combination in total. See `Ash.Query.Combination` for more on creating combination queries. ### Example ```elixir # Top ten users not on a losing streak and top ten users who are not on a winning streak User |> Ash.Query.filter(active == true) |> Ash.Query.combination_of([ # must always begin with a base combination Ash.Query.Combination.base( sort: [score: :desc], filter: expr(not(on_a_losing_streak)), limit: 10 ), Ash.Query.Combination.union( sort: [score: :asc], filter: expr(not(on_a_winning_streak)), limit: 10 ) ]) |> Ash.read!() ``` ### Select and calculations There is no `select` available for combinations, instead the select of the outer query is used for each combination. However, you can use the `calculations` field in `Ash.Query.Combination` to add expression calculations. Those calculations can "overwrite" a selected attribute, or can introduce a new field. Note that, for SQL data layers, all combinations will be required to have the same number of fields in their SELECT statement, which means that if one combination adds a calculation, all of the others must also add that calculation. In this example, we compute separate match scores ```elixir query = "fred" User |> Ash.Query.filter(active == true) |> Ash.Query.combination_of([ # must always begin with a base combination Ash.Query.Combination.base( filter: expr(trigram_similarity(user_name, ^query) >= 0.5), calculate: %{ match_score: trigram_similarity(user_name, ^query) }, sort: [ calc(trigram_similarity(user_name, ^query), :desc) ], limit: 10 ), Ash.Query.Combination.union( filter: expr(trigram_similarity(email, ^query) >= 0.5), calculate: %{ match_score: trigram_similarity(email, ^query) }, sort: [ calc(trigram_similarity(email, ^query), :desc) ], limit: 10 ) ]) |> Ash.read!() ``` """ @spec combination_of(t(), Ash.Query.Combination.t() | [Ash.Query.Combination.t()]) :: t() def combination_of(query, combinations) do query = new(query) %{query | combination_of: query.combination_of ++ List.wrap(combinations)} end @doc """ Attach a sort statement to the query labelled as user input. Sorts added as user input (or filters constructed with `Ash.Filter.parse_input`) will honor any field policies on resources by replacing any references to the field with `nil` in cases where the actor should not be able to see the given field. See `Ash.Query.sort/3` for more information on accepted formats. """ def sort_input(query, sorts, opts \\ []) do query = new(query) if sorts == [] || sorts == nil do query else if Ash.DataLayer.data_layer_can?(query.resource, :sort) do if opts[:prepend?] && query.sort != [] do validated = query |> Map.put(:sort, []) |> sort_input(sorts) |> Map.get(:sort) new_sort_input_indices = Enum.to_list(0..(Enum.count(List.wrap(validated)) - 1)) ++ Enum.map(query.sort_input_indices, &(&1 + 1)) %{query | sort: validated ++ query.sort, sort_input_indices: new_sort_input_indices} else last_index = Enum.count(List.wrap(query.sort)) case Ash.Sort.parse_input(query.resource, sorts) do {:ok, sorts} -> sorts |> List.wrap() |> Enum.with_index(last_index) |> Enum.reduce(query, fn {{sort, direction}, index}, query -> %{ query | sort: query.sort ++ [{sort, direction}], sort_input_indices: query.sort_input_indices ++ [index] } {sort, index}, query -> %{ query | sort: query.sort ++ [{sort, :asc}], sort_input_indices: query.sort_input_indices ++ [index] } end) {:error, error} -> Ash.Query.add_error(query, :sort, error) end end else add_error(query, :sort, "Data layer does not support sorting") end end |> sequence_sorts() end defp sequence_sorts(query) do %{ query | sort: sequence_sort(query.sort), distinct_sort: sequence_sort(query.distinct_sort), distinct: sequence_sort(query.distinct) } end defp sequence_sort(nil), do: nil # sobelow_skip ["DOS.BinToAtom", "DOS.StringToAtom"] defp sequence_sort(statement) do statement |> Enum.with_index() |> Enum.map(fn {{%Ash.Query.Calculation{name: :__calc__} = field, direction}, index} -> {%{field | name: String.to_atom("__calc__#{index}"), load: nil}, direction} {other, _} -> other end) end @doc """ Attach a filter statement to the query. The filter is applied as an "and" to any filters currently on the query. Filters allow you to specify conditions that records must meet to be included in the query results. Multiple filters on the same query are combined with "and" logic. ## Examples # Filter with simple equality MyApp.Post |> Ash.Query.filter(published: true) # Filter with comparison operators MyApp.Post |> Ash.Query.filter(view_count > 100) # Filter with complex expressions using do block MyApp.Post |> Ash.Query.filter do published == true and view_count > 100 end ## See also - `Ash.Filter` for comprehensive filter documentation - `sort/3` for ordering query results - `Ash.read/2` for executing filtered queries """ defmacro filter(query, %Ash.Filter{} = filter) do quote location: :keep do Ash.Query.do_filter(unquote(query), unquote(filter)) end end defmacro filter(query, nil), do: query defmacro filter(query, true), do: query defmacro filter(query, false) do quote location: :keep do Ash.Query.do_filter(unquote(query), false) end end defmacro filter(query, do: body) do quote location: :keep do Ash.Query.do_filter(unquote(query), unquote(body)) end end defmacro filter(query, expression) do if Keyword.keyword?(expression) do quote location: :keep do Ash.Query.do_filter(unquote(query), unquote(expression)) end else quote location: :keep do require Ash.Expr expr = Ash.Expr.expr(unquote(expression)) Ash.Query.do_filter(unquote(query), expr) end end end @doc """ Creates a new query for the given resource. This is the starting point for building queries. The query will automatically include the resource's base filter and default context. ## Examples # Create a new query for a resource iex> Ash.Query.new(MyApp.Post) %Ash.Query{resource: MyApp.Post, ...} # Create a query with options iex> Ash.Query.new(MyApp.Post, domain: MyApp.Blog) %Ash.Query{resource: MyApp.Post, domain: MyApp.Blog, ...} # Pass an existing query (returns the query unchanged) iex> query = Ash.Query.new(MyApp.Post) iex> Ash.Query.new(query) %Ash.Query{resource: MyApp.Post, ...} ## See also - `for_read/4` for creating queries bound to specific read actions - `filter/2` for adding filter conditions - `sort/3` for adding sort criteria - [Read Actions Guide](/documentation/topics/actions/read-actions.md) for understanding read operations - [Actions Guide](/documentation/topics/actions/actions.md) for general action concepts """ @spec new(Ash.Resource.t() | Ash.Query.t(), opts :: Keyword.t()) :: Ash.Query.t() def new(resource, opts \\ []) def new(%__MODULE__{} = query, _opts), do: query def new(resource, opts) when is_atom(resource) do if !Ash.Resource.Info.resource?(resource) do raise ArgumentError, "Expected a resource or a query in `Ash.Query.new/2`, got: `#{inspect(resource)}`" end query = %__MODULE__{ domain: opts[:domain], filter: nil, resource: resource } query = case Ash.Resource.Info.base_filter(resource) do nil -> query filter -> if Keyword.get(opts, :base_filter?, true) do filter = resource |> Ash.Filter.parse!(filter, query.context) |> Ash.Filter.embed_predicates() do_filter(query, filter) else query end end case Ash.Resource.Info.default_context(resource) do nil -> query context -> Ash.Query.set_context(query, context) end context = Process.get(:ash_context, %{}) || %{} query |> set_context(context) |> Ash.DataLayer.transform_query() end def new(resource, _) do raise ArgumentError, "Expected a resource or a query in `Ash.Query.new/2`, got: `#{inspect(resource)}`" end @for_read_opts [ actor: [ type: :any, doc: "set the actor, which can be used in any `Ash.Resource.Change`s configured on the action. (in the `context` argument)" ], scope: [ type: :any, doc: "A value that implements the `Ash.Scope.ToOpts` protocol, for passing around actor/tenant/context in a single value. See `Ash.Scope.ToOpts` for more." ], authorize?: [ type: :boolean, doc: "set authorize?, which can be used in any `Ash.Resource.Change`s configured on the action. (in the `context` argument)" ], tracer: [ type: {:wrap_list, {:behaviour, Ash.Tracer}}, doc: "A tracer to use. Will be carried over to the action. For more information see `Ash.Tracer`." ], tenant: [ type: {:protocol, Ash.ToTenant}, doc: "set the tenant on the query" ], load: [ type: :any, doc: "A load statement to apply to the query" ], skip_unknown_inputs: [ type: {:wrap_list, {:or, [:atom, :string]}}, doc: "A list of inputs that, if provided, will be ignored if they are not recognized by the action. Use `:*` to indicate all unknown keys." ], context: [ type: :map, doc: "A map of context to set on the query. This will be merged with any context set on the query itself." ] ] @doc false def for_read_opts, do: @for_read_opts @doc """ Creates a query for a given read action and prepares it. This function configures the query to use a specific read action with the provided arguments and options. The query will be validated and prepared according to the action's configuration, including applying preparations and action filters. Multitenancy is *not* validated until an action is called. This allows you to avoid specifying a tenant until just before calling the domain action. ## Examples # Create a query for a simple read action iex> Ash.Query.for_read(MyApp.Post, :read) %Ash.Query{action: %{name: :read}, ...} # Create a query with arguments for a parameterized action iex> Ash.Query.for_read(MyApp.Post, :published, %{since: ~D[2023-01-01]}) %Ash.Query{action: %{name: :published}, arguments: %{since: ~D[2023-01-01]}, ...} # Create a query with options iex> Ash.Query.for_read(MyApp.Post, :read, %{}, actor: current_user, authorize?: true) %Ash.Query{action: %{name: :read}, ...} ## Options #{Spark.Options.docs(@for_read_opts)} ## See also - `Ash.read/2` for executing the prepared query - `new/2` for creating basic queries without specific actions - `load/3` for adding relationship loading to queries - `d:Ash.Resource.Dsl.actions.read` for defining read actions - [Read Actions Guide](/documentation/topics/actions/read-actions.md) for understanding read operations - [Actions Guide](/documentation/topics/actions/actions.md) for general action concepts """ @spec for_read(t() | Ash.Resource.t(), atom(), map() | Keyword.t(), Keyword.t()) :: t() # 4.0: make args required, same with action input and changeset def for_read(query, action_name, args \\ %{}, opts \\ []) do query = new(query) domain = query.domain || opts[:domain] || Ash.Resource.Info.domain(query.resource) || Ash.Actions.Helpers.maybe_embedded_domain(query.resource) || raise ArgumentError, "Could not determine domain for query. Provide the `domain` option or configure a domain in the resource directly." {query, opts} = Ash.Actions.Helpers.set_context_and_get_opts( domain, query, opts ) query = query |> Map.put(:params, Map.merge(query.params, Map.new(args))) |> set_context(Keyword.get(opts, :context, %{})) action = Ash.Resource.Info.action(query.resource, action_name, :read) if action do name = fn -> "query:" <> Ash.Resource.Info.trace_name(query.resource) <> ":#{action_name}" end query = if opts[:load] do load(query, opts[:load]) else query end Ash.Tracer.span :query, name, opts[:tracer] do Ash.Tracer.telemetry_span [:ash, :query], fn -> %{ resource_short_name: Ash.Resource.Info.short_name(query.resource) } end do metadata = fn -> %{ resource_short_name: Ash.Resource.Info.short_name(query.resource), resource: query.resource, actor: opts[:actor], tenant: opts[:tenant], action: action.name, authorize?: opts[:authorize?] } end Ash.Tracer.set_metadata(opts[:tracer], :query, metadata) query |> Map.put(:action, action) |> reset_arguments() |> timeout(query.timeout || opts[:timeout]) |> set_actor(opts) |> set_authorize?(opts) |> set_tracer(opts) |> set_tenant(opts[:tenant] || query.tenant) |> cast_params(action, args, opts) |> set_argument_defaults(action) |> require_arguments(action) |> run_preparations(action, opts[:actor], opts[:authorize?], opts[:tracer], metadata) |> add_action_filters(action, opts[:actor]) |> Map.put(:__validated_for_action__, action_name) end end else raise_no_action(query.resource, action_name) end end @doc """ Set a timeout for the query. For more information, see the [timeouts guide](/documentation/topics/advanced/timeouts.md) """ @spec timeout(t(), pos_integer() | :infinity | nil) :: t() def timeout(query, timeout) do query = new(query) if Ash.DataLayer.data_layer_can?(query.resource, :timeout) || is_nil(timeout) do %{query | timeout: timeout} else add_error(query, TimeoutNotSupported.exception(resource: query.resource)) end end @doc false def set_actor(query, opts) do if Keyword.has_key?(opts, :actor) do put_context(query, :private, %{actor: opts[:actor]}) else query end end @doc false def set_authorize?(query, opts) do if Keyword.has_key?(opts, :authorize?) do put_context(query, :private, %{authorize?: opts[:authorize?]}) else query end end @doc false def set_tracer(query, opts) do if Keyword.has_key?(opts, :tracer) do put_context(query, :private, %{tracer: opts[:tracer]}) else query end end defp raise_no_action(resource, action_name) do available_actions = resource |> Ash.Resource.Info.actions() |> Enum.filter(&(&1.type == :read)) |> Enum.map_join("\n", &" - `#{inspect(&1.name)}") raise ArgumentError, message: """ No such read action on resource #{inspect(resource)}: #{String.slice(inspect(action_name), 0..50)} Example Call: Ash.Query.for_read(query_or_resource, :action_name, input, options) Available read actions: #{available_actions} """ end defp require_arguments(query, action) do action.arguments |> Enum.filter(&(&1.allow_nil? == false)) |> Enum.reduce(query, fn argument, query -> case fetch_argument(query, argument.name) do {:ok, value} when not is_nil(value) -> query _ -> if argument.name in query.invalid_keys do query else add_error( query, Required.exception( resource: query.resource, field: argument.name, type: :argument ) ) end end end) end defp set_argument_defaults(query, action) do Enum.reduce(action.arguments, query, fn argument, query -> case fetch_argument(query, argument.name) do :error -> if is_nil(argument.default) do query else %{ query | arguments: Map.put(query.arguments, argument.name, argument_default(argument.default)) } end _ -> query end end) end defp cast_params(query, action, args, opts) do skip_unknown_inputs = List.wrap(opts[:skip_unknown_inputs] || action.skip_unknown_inputs) Enum.reduce(args, query, fn {name, value}, query -> cond do has_argument?(action, name) -> set_argument(query, name, value) :* in skip_unknown_inputs -> query name in skip_unknown_inputs -> query match?("_" <> _, name) -> query true -> error = Ash.Error.Invalid.NoSuchInput.exception( resource: query.resource, action: query.action.name, input: name, inputs: Enum.map(query.action.arguments, & &1.name) ) add_error(query, Ash.Error.set_path(error, name)) end end) end defp has_argument?(action, name) when is_atom(name) do Enum.any?(action.arguments, &(&1.public? && &1.name == name)) end defp has_argument?(action, name) when is_binary(name) do Enum.any?(action.arguments, &(&1.public? && to_string(&1.name) == name)) end defp has_key?(map, key) when is_map(map), do: Map.has_key?(map, key) defp has_key?(keyword, key), do: Keyword.has_key?(keyword, key) defp run_preparations(query, action, actor, authorize?, tracer, metadata) do global_validations = if action.skip_global_validations? do [] else Ash.Resource.Info.validations(query.resource, :read) end query.resource # 4.0 make global preparations happen # after action level preparations |> Ash.Resource.Info.preparations() |> Enum.concat(action.preparations || []) |> Enum.concat(global_validations) |> Enum.reduce(query, fn %{only_when_valid?: true}, %{valid?: false} = query -> query %{validation: {module, opts}} = validation, query -> if __MODULE__ not in module.supports(opts) do raise Ash.Error.Framework.UnsupportedSubject, subject: __MODULE__, module: module end validate(query, validation, tracer, metadata, actor) %{preparation: _} = preparation, query -> run_preparation(preparation, query, actor, authorize?, tracer, metadata) end) end defp validate(query, validation, tracer, metadata, actor) do if validation.before_action? do before_action(query, fn query -> if validation.only_when_valid? and not query.valid? do query else do_validation(query, validation, tracer, metadata, actor) end end) else if validation.only_when_valid? and not query.valid? do query else do_validation(query, validation, tracer, metadata, actor) end end end defp do_validation(query, validation, tracer, metadata, actor) do context = %{ actor: query.context[:private][:actor], tenant: query.tenant, source_context: query.context, authorize?: query.context[:private][:authorize?] || false, tracer: query.context[:private][:tracer] } if Enum.all?(validation.where || [], fn {module, opts} -> if __MODULE__ not in module.supports(opts) do raise Ash.Error.Framework.UnsupportedSubject, subject: __MODULE__, module: module end opts = Ash.Expr.fill_template( opts, actor: actor, tenant: query.to_tenant, args: query.arguments, context: query.context ) case Ash.Resource.Validation.init(module, opts) do {:ok, opts} -> Ash.Resource.Validation.validate( module, query, opts, struct(Ash.Resource.Validation.Context, context) ) == :ok _ -> false end end) do Ash.Tracer.span :validation, fn -> "validate: #{inspect(validation.module)}" end, tracer do Ash.Tracer.telemetry_span [:ash, :validation], fn -> %{ resource_short_name: Ash.Resource.Info.short_name(query.resource), validation: inspect(validation.module) } end do Ash.Tracer.set_metadata(tracer, :validation, metadata) opts = Ash.Expr.fill_template( validation.opts, actor: actor, tenant: query.to_tenant, args: query.arguments, context: query.context ) with {:ok, opts} <- Ash.Resource.Validation.init(validation.module, opts), :ok <- Ash.Resource.Validation.validate( validation.module, query, opts, struct( Ash.Resource.Validation.Context, Map.put(context, :message, validation.message) ) ) do query else :ok -> query {:error, error} when is_binary(error) -> add_error(query, validation.message || error) {:error, error} when is_exception(error) -> if validation.message do error = Ash.Error.override_validation_message(error, validation.message) add_error(query, error) else add_error(query, error) end {:error, errors} when is_list(errors) -> if validation.message do errors = Enum.map(errors, fn error -> Ash.Error.override_validation_message(error, validation.message) end) add_error(query, errors) else add_error(query, errors) end {:error, error} -> error = if Keyword.keyword?(error) do Keyword.put(error, :message, validation.message || error[:message]) else validation.message || error end add_error(query, error) end end end else query end end defp run_preparation( %{preparation: {module, opts}} = preparation, query, actor, authorize?, tracer, metadata ) do context = %{ actor: actor, tenant: query.tenant, source_context: query.context, authorize?: authorize? || false, tracer: tracer } if Enum.all?(preparation.where || [], fn {module, opts} -> if __MODULE__ not in module.supports(opts) do raise Ash.Error.Framework.UnsupportedSubject, subject: __MODULE__, module: module end opts = Ash.Expr.fill_template( opts, actor: actor, tenant: query.to_tenant, args: query.arguments, context: query.context ) case Ash.Resource.Validation.init(module, opts) do {:ok, opts} -> Ash.Resource.Validation.validate( module, query, opts, struct(Ash.Resource.Validation.Context, context) ) == :ok _ -> false end end) do Ash.Tracer.span :preparation, fn -> "prepare: #{inspect(module)}" end, tracer do Ash.Tracer.telemetry_span [:ash, :preparation], fn -> %{ resource_short_name: Ash.Resource.Info.short_name(query.resource), preparation: inspect(module) } end do Ash.Tracer.set_metadata(tracer, :preparation, metadata) {:ok, opts} = Ash.Resource.Preparation.init(module, opts) opts = Ash.Expr.fill_template( opts, actor: actor, tenant: query.to_tenant, args: query.arguments, context: query.context ) preparation_context = struct(Ash.Resource.Preparation.Context, context) Ash.Resource.Preparation.prepare(module, query, opts, preparation_context) end end else query end end @doc """ Adds a before_transaction hook to the query. The before_transaction hook runs before the database transaction begins. It receives the query and must return either a modified query or an error. ## Examples # Add logging before transaction iex> query = MyApp.Post |> Ash.Query.before_transaction(fn query -> ...> IO.puts("Starting transaction for \#{inspect(query.resource)}") ...> query ...> end) ## See also - `after_transaction/2` for hooks that run after the transaction - `around_transaction/2` for hooks that wrap the entire transaction - `before_action/3` for hooks that run before the action (inside transaction) """ @spec before_transaction( query :: t(), fun :: before_transaction_fun(), opts :: Keyword.t() ) :: t() def before_transaction(query, func, opts \\ []) do query = new(query) if opts[:prepend?] do %{query | before_transaction: [func | query.before_transaction]} else %{query | before_transaction: query.before_transaction ++ [func]} end end @doc """ Adds an after_transaction hook to the query. The after_transaction hook runs after the database transaction completes, regardless of success or failure. It receives the query and the result, and can modify the result or perform cleanup operations. ## Examples # Add cleanup after transaction iex> query = MyApp.Post |> Ash.Query.after_transaction(fn query, result -> ...> cleanup_resources() ...> result ...> end) ## See also - `before_transaction/2` for hooks that run before the transaction - `around_transaction/2` for hooks that wrap the entire transaction - `after_action/2` for hooks that run after the action (inside transaction) """ @spec after_transaction( query :: t(), fun :: after_transaction_fun(), opts :: Keyword.t() ) :: t() def after_transaction(query, func, opts \\ []) do query = new(query) if opts[:prepend?] do %{query | after_transaction: [func | query.after_transaction]} else %{query | after_transaction: query.after_transaction ++ [func]} end end @doc """ Adds an around_transaction hook to the query. Your function will get the query, and a callback that must be called with a query (that may be modified). The callback will return `{:ok, results}` or `{:error, error}`. You can modify these values, but the return value must be one of those types. The around_transaction calls happen first, and then (after they each resolve their callbacks) the `before_action` hooks are called, followed by the `after_action` hooks being run. Then, the code that appeared *after* the callbacks were called is then run. ## Examples # Add logging around the transaction iex> query = MyApp.Post |> Ash.Query.around_transaction(fn query, callback -> ...> IO.puts("Starting transaction for \#{inspect(query.resource)}") ...> result = callback.(query) ...> IO.puts("Transaction completed: \#{inspect(result)}") ...> result ...> end) # Add error handling and retry logic iex> query = MyApp.Post |> Ash.Query.around_transaction(fn query, callback -> ...> case callback.(query) do ...> {:ok, results} = success -> success ...> {:error, %{retryable?: true}} -> ...> callback.(query) # Retry once ...> error -> error ...> end ...> end) ## Warning Using this without understanding how it works can cause big problems. You *must* call the callback function that is provided to your hook, and the return value must contain the same structure that was given to you, i.e `{:ok, result_of_action}`. ## See also - `before_transaction/2` for hooks that run before the transaction - `after_transaction/2` for hooks that run after the transaction - `before_action/3` for hooks that run before the action executes - `after_action/2` for hooks that run after the action completes - `Ash.read/2` for executing queries with hooks """ @spec around_transaction( query :: t(), fun :: around_transaction_fun(), opts :: Keyword.t() ) :: t() def around_transaction(query, func, opts \\ []) do query = new(query) if opts[:prepend?] do %{query | around_transaction: [func | query.around_transaction]} else %{query | around_transaction: query.around_transaction ++ [func]} end end @doc """ Adds a before_action hook to the query. Before action hooks are called after preparations but before the actual data layer query is executed. They receive the prepared query and can modify it or perform side effects before the action runs. ## Examples # Add validation before the query runs iex> query = MyApp.Post ...> |> Ash.Query.before_action(fn query -> ...> if Enum.empty?(query.sort) do ...> Ash.Query.sort(query, :created_at) ...> else ...> query ...> end ...> end) # Add logging before the action iex> query = MyApp.Post ...> |> Ash.Query.before_action(fn query -> ...> IO.puts("Executing query for \#{length(query.filter || [])} filters") ...> query ...> end) # Prepend a hook to run first iex> query = MyApp.Post ...> |> Ash.Query.before_action(&setup_query/1) ...> |> Ash.Query.before_action(&early_validation/1, prepend?: true) ## Options - `prepend?` - when `true`, places the hook before all other hooks instead of after ## See also - `after_action/2` for hooks that run after the action completes - `around_transaction/2` for hooks that wrap the entire transaction - `Ash.read/2` for executing queries with hooks """ @spec before_action( query :: t(), fun :: (t() -> t() | {t(), list(Ash.Notifier.Notification.t())}), opts :: Keyword.t() ) :: t() def before_action(query, func, opts \\ []) do query = new(query) if opts[:prepend?] do %{query | before_action: [func | query.before_action]} else %{query | before_action: query.before_action ++ [func]} end end @doc false @spec authorize_results( t(), (t(), [Ash.Resource.record()] -> {:ok, [Ash.Resource.record()]} | {:ok, [Ash.Resource.record()], list(Ash.Notifier.Notification.t())} | {:error, term}) ) :: t() def authorize_results(query, func) do query = new(query) %{query | authorize_results: [func | query.authorize_results]} end # remove when 4.0 happens and `@read_action_after_action_hooks_in_order?` goes away @dialyzer {:nowarn_function, after_action: 2} @doc """ Adds an after_action hook to the query. After action hooks are called with the query and the list of records returned from the action. They can modify the records, perform side effects, or return errors to halt processing. The hook can return notifications alongside the records. ## Examples # Transform records after loading iex> query = MyApp.Post ...> |> Ash.Query.after_action(fn query, records -> ...> enriched_records = Enum.map(records, &add_computed_field/1) ...> {:ok, enriched_records} ...> end) # Log successful reads iex> query = MyApp.Post ...> |> Ash.Query.after_action(fn query, records -> ...> IO.puts("Successfully loaded \#{length(records)} posts") ...> {:ok, records} ...> end) # Add notifications after the action iex> query = MyApp.Post ...> |> Ash.Query.after_action(fn query, records -> ...> notifications = create_read_notifications(records) ...> {:ok, records, notifications} ...> end) # Validate results and potentially error iex> query = MyApp.Post ...> |> Ash.Query.after_action(fn query, records -> ...> if Enum.any?(records, &restricted?/1) do ...> {:error, "Access denied to restricted posts"} ...> else ...> {:ok, records} ...> end ...> end) ## See also - `before_action/3` for hooks that run before the action executes - `around_transaction/2` for hooks that wrap the entire transaction - `Ash.read/2` for executing queries with hooks """ @spec after_action( query :: t(), fun :: (t(), [Ash.Resource.record()] -> {:ok, [Ash.Resource.record()]} | {:ok, [Ash.Resource.record()], list(Ash.Notifier.Notification.t())} | {:error, term}) ) :: t() # in 4.0, add an option to prepend hooks def after_action(query, func) do query = new(query) if @read_action_after_action_hooks_in_order? do %{query | after_action: query.after_action ++ [func]} else %{query | after_action: [func | query.after_action]} end end defp add_action_filters(query, %{filter: nil}, _actor), do: query defp add_action_filters(query, action, actor) do if Ash.Expr.template_references_actor?(action.filter) and is_nil(actor) do Ash.Query.add_error(query, ReadActionRequiresActor.exception([])) else built_filter = Ash.Expr.fill_template( action.filter, actor: actor, tenant: query.to_tenant, args: query.arguments, context: query.context ) do_filter(query, built_filter) end end @doc """ Ensure that only the specified *attributes* are present in the results. The first call to `select/2` will replace the default behavior of selecting all attributes. Subsequent calls to `select/2` will combine the provided fields unless the `replace?` option is provided with a value of `true`. If a field has been deselected, selecting it again will override that (because a single list of fields is tracked for selection) Primary key attributes are always selected and cannot be deselected. When attempting to load a relationship (or manage it with `Ash.Changeset.manage_relationship/3`), if the source field is not selected on the query/provided data an error will be produced. If loading a relationship with a query, an error is produced if the query does not select the destination field of the relationship. Use `ensure_selected/2` if you wish to make sure a field has been selected, without deselecting any other fields. ## Examples # Select specific attributes iex> MyApp.Post |> Ash.Query.select([:title, :content]) %Ash.Query{select: [:id, :title, :content], ...} # Select additional attributes (combines with existing selection) iex> MyApp.Post ...> |> Ash.Query.select([:title]) ...> |> Ash.Query.select([:content]) %Ash.Query{select: [:id, :title, :content], ...} # Replace existing selection iex> MyApp.Post ...> |> Ash.Query.select([:title]) ...> |> Ash.Query.select([:content], replace?: true) %Ash.Query{select: [:id, :content], ...} ## See also - `ensure_selected/2` for adding fields without deselecting others - `deselect/2` for removing specific fields from selection - `load/3` for loading relationships and calculations """ @spec select(t() | Ash.Resource.t(), list(atom) | atom, Keyword.t()) :: t() def select(query, fields, opts \\ []) do fields = case fields do %MapSet{} = fields -> fields fields -> MapSet.new(List.wrap(fields)) end query = new(query) existing_fields = Ash.Resource.Info.attribute_names(query.resource) valid_fields = MapSet.intersection(fields, existing_fields) query = if MapSet.size(valid_fields) != MapSet.size(fields) do MapSet.difference(fields, existing_fields) |> Enum.reduce(query, fn field, query -> Ash.Query.add_error( query, Ash.Error.Query.NoSuchAttribute.exception(resource: query.resource, attribute: field) ) end) else query end select = valid_fields |> MapSet.union(Ash.Resource.Info.always_selected_attribute_names(query.resource)) |> MapSet.union(MapSet.new(Ash.Resource.Info.primary_key(query.resource))) new_select = if opts[:replace?] do select else MapSet.union(MapSet.new(query.select || []), select) end %{query | select: MapSet.to_list(new_select)} end @doc """ Determines if the filter statement of a query is equivalent to the provided expression. This uses the satisfiability solver that is used when solving for policy authorizations. In complex scenarios, or when using custom database expressions, (like fragments in ash_postgres), this function may return `:maybe`. Use `supserset_of?` to always return a boolean. """ defmacro equivalent_to(query, expr) do quote do require Ash.Expr query = unquote(query) expr = unquote(Ash.Expr.do_expr(expr)) require Ash.Query case Ash.Query.superset_of(query, expr) do :maybe -> :maybe true -> Ash.Query.subset_of(query, expr) false -> false end end end @doc """ Same as `equivalent_to/2` but always returns a boolean. `:maybe` returns `false`. """ defmacro equivalent_to?(query, expr) do quote do Ash.Query.equivalent_to(unquote(query), unquote(expr)) == true end end @doc """ Determines if the provided expression would return data that is a subset of the data returned by the filter on the query. This uses the satisfiability solver that is used when solving for policy authorizations. In complex scenarios, or when using custom database expressions, (like fragments in ash_postgres), this function may return `:maybe`. Use `supserset_of?` to always return a boolean. """ defmacro superset_of(query, expr) do quote do query = unquote(query) require Ash.Expr expr = unquote(Ash.Expr.do_expr(expr)) left_filter = query.filter {:ok, left_expression} = Ash.Filter.hydrate_refs(left_filter.expression, %{ resource: query.resource, aggregates: query.aggregates, calculations: query.calculations, public?: false }) left_filter = %{left_filter | expression: left_expression} {:ok, right_expression} = Ash.Filter.hydrate_refs(expr, %{ resource: query.resource, aggregates: query.aggregates, calculations: query.calculations, public?: false }) right_filter = %{left_filter | expression: right_expression} Ash.Filter.strict_subset(left_filter, right_filter) end end @doc """ Same as `superset_of/2` but always returns a boolean. `:maybe` returns `false`. """ defmacro superset_of?(query, expr) do quote do Ash.Query.superset_of(unquote(query), unquote(expr)) == true end end @doc """ Determines if the provided expression would return data that is a subset of the data returned by the filter on the query. This uses the satisfiability solver that is used when solving for policy authorizations. In complex scenarios, or when using custom database expressions, (like fragments in ash_postgres), this function may return `:maybe`. Use `subset_of?` to always return a boolean. """ defmacro subset_of(query, expr) do quote do query = unquote(query) require Ash.Expr expr = unquote(Ash.Expr.do_expr(expr)) right_filter = query.filter {:ok, right_expression} = Ash.Filter.hydrate_refs(right_filter.expression, %{ resource: query.resource, aggregates: query.aggregates, calculations: query.calculations, public?: false }) right_filter = %{right_filter | expression: right_expression} {:ok, left_expression} = Ash.Filter.hydrate_refs(expr, %{ resource: query.resource, aggregates: query.aggregates, calculations: query.calculations, public?: false }) left_filter = %{right_filter | expression: left_expression} Ash.Filter.strict_subset(left_filter, right_filter) end end @doc """ Same as `subset_of/2` but always returns a boolean. `:maybe` returns `false`. """ defmacro subset_of?(query, expr) do quote do Ash.Query.subset_of(unquote(query), unquote(expr)) == true end end @doc """ Ensures that the given attributes are selected. The first call to `select/2` will *limit* the fields to only the provided fields. Use `ensure_selected/2` to say "select this field (or these fields) without deselecting anything else". This function is additive - it will not remove any fields that are already selected. ## Examples # Ensure specific fields are selected (additive) iex> MyApp.Post |> Ash.Query.ensure_selected([:title]) %Ash.Query{select: [:id, :title, :content, :created_at], ...} # Add to existing selection iex> MyApp.Post ...> |> Ash.Query.select([:title]) ...> |> Ash.Query.ensure_selected([:content, :author_id]) %Ash.Query{select: [:id, :title, :content, :author_id], ...} # Ensure fields for relationship loading iex> MyApp.Post ...> |> Ash.Query.ensure_selected([:author_id]) ...> |> Ash.Query.load(:author) %Ash.Query{select: [..., :author_id], load: [author: []], ...} ## See also - `select/3` for explicitly controlling field selection - `deselect/2` for removing specific fields from selection - `load/3` for loading relationships that may require specific fields """ @spec ensure_selected(t() | Ash.Resource.t(), list(atom) | atom) :: t() def ensure_selected(query, fields) do query = new(query) if query.select do Ash.Query.select(query, List.wrap(fields)) else default_attributes = Ash.Resource.Info.selected_by_default_attribute_names(query.resource) query |> Ash.Query.select(default_attributes) |> Ash.Query.select(List.wrap(fields)) end end @doc """ Returns a list of attributes, aggregates, relationships, and calculations that are being loaded Provide a list of field types to narrow down the returned results. """ def accessing( query, types \\ [:attributes, :relationships, :calculations, :aggregates], only_public? \\ true ) do query.resource |> Ash.Resource.Info.fields(types) |> then(fn fields -> if only_public? do Stream.filter(fields, & &1.public?) else fields end end) |> Stream.map(& &1.name) |> Enum.filter(&loading?(query, &1)) end @doc """ Ensures that the specified attributes are `nil` in the query results. This function removes specified fields from the selection, causing them to be excluded from the query results. If no fields are currently selected (meaning all fields would be returned by default), this will first select all default fields and then remove the specified ones. ## Examples # Remove specific fields from results iex> MyApp.Post |> Ash.Query.deselect([:content]) %Ash.Query{select: [:id, :title, :created_at, ...], ...} # Remove multiple fields iex> MyApp.Post |> Ash.Query.deselect([:content, :metadata]) %Ash.Query{select: [:id, :title, :created_at, ...], ...} # Deselect from existing selection iex> MyApp.Post ...> |> Ash.Query.select([:title, :content, :author_id]) ...> |> Ash.Query.deselect([:content]) %Ash.Query{select: [:id, :title, :author_id], ...} # Deselect empty list (no-op) iex> MyApp.Post |> Ash.Query.deselect([]) %Ash.Query{...} ## See also - `select/3` for explicitly controlling field selection - `ensure_selected/2` for adding fields without removing others - Primary key fields cannot be deselected and will always be included """ @spec deselect(t() | Ash.Resource.t(), list(atom)) :: t() def deselect(query, []), do: new(query) def deselect(query, fields) do query = new(query) select = if query.select do query.select -- List.wrap(fields) else MapSet.difference( Ash.Resource.Info.selected_by_default_attribute_names(query.resource), MapSet.new(List.wrap(fields)) ) end select(query, select, replace?: true) end @doc """ Checks if a specific field is currently selected in the query. Returns `true` if the field will be included in the query results, either because it's explicitly selected, it's selected by default, or it's a primary key field (which are always selected). ## Examples # Check selection when no explicit select is set (uses defaults) iex> query = MyApp.Post |> Ash.Query.new() iex> Ash.Query.selecting?(query, :title) true # Check selection with explicit select iex> query = MyApp.Post |> Ash.Query.select([:title, :content]) iex> Ash.Query.selecting?(query, :title) true iex> Ash.Query.selecting?(query, :metadata) false # Primary key fields are always selected iex> query = MyApp.Post |> Ash.Query.select([:title]) iex> Ash.Query.selecting?(query, :id) # assuming :id is primary key true ## See also - `select/3` for controlling field selection - `ensure_selected/2` for adding fields to selection - `load/3` for loading relationships that may require specific fields """ @spec selecting?(t(), atom()) :: boolean() def selecting?(query, field) do case query.select do nil -> query.resource |> Ash.Resource.Info.attribute(field) |> case do %{select_by_default?: true} -> true _ -> false end select -> if field in select do true else attribute = Ash.Resource.Info.attribute(query.resource, field) attribute && attribute.primary_key? end end || loading?(query, field) end @doc """ Returns true if the field/relationship or path to field/relationship is being loaded. It accepts an atom or a list of atoms, which is treated for as a "path", i.e: Resource |> Ash.Query.load(friends: [enemies: [:score]]) |> Ash.Query.loading?([:friends, :enemies, :score]) iex> true Resource |> Ash.Query.load(friends: [enemies: [:score]]) |> Ash.Query.loading?([:friends, :score]) iex> false Resource |> Ash.Query.load(friends: [enemies: [:score]]) |> Ash.Query.loading?(:friends) iex> true """ def loading?(query, [last]) do loading?(query, last) end def loading?(query, [first | rest]) do case Keyword.get(query.load || [], first) do %Ash.Query{} = next -> loading?(next, rest) nil -> false other -> raise "Cannot check if loading path #{inspect(rest)} of #{inspect(other)}" end || loading_through?(query, [first | rest]) end def loading?(query, item) when is_atom(item) do selecting? = if Ash.Resource.Info.attribute(query.resource, item) do is_nil(query.select) || item in query.select end selecting? || has_key?(query.load || [], item) || Enum.any?(query.calculations, fn {_, %{module: Ash.Resource.Calculation.LoadRelationship, opts: opts}} -> opts[:relationship] == item {_, %{module: Ash.Resource.Calculation.LoadAttribute, opts: opts}} -> opts[:attribute] == item {_, %{calc_name: calc_name}} -> calc_name == item end) || Enum.any?(query.aggregates, fn {_, %{agg_name: agg_name}} -> agg_name == item end) end defp loading_through?(query, [first | rest]) do Enum.any?(query.calculations, fn {_, %{module: Ash.Resource.Calculation.LoadRelationship, opts: opts}} -> if opts[:relationship] == first do if opts[:query] do Ash.Query.loading?(opts[:query], rest) end end {_, %{module: Ash.Resource.Calculation.LoadAttribute, opts: opts}} -> opts[:attribute] == first && opts[:load] && loading_via_keyword?(opts[:load], rest) end) end defp loading_via_keyword?(keyword, item) when is_atom(item) do Keyword.keyword?(keyword) and Keyword.has_key?(keyword, item) end defp loading_via_keyword?(keyword, [item]) do loading_via_keyword?(keyword, item) end defp loading_via_keyword?(keyword, [first | rest]) do Keyword.keyword?(keyword) and Enum.any?(keyword, fn {key, next} -> key == first && loading_via_keyword?(next, rest) end) end @doc """ Adds a load statement to the result of an attribute or calculation. Uses `Ash.Type.load/5` to request that the type load nested data. """ def load_through(query, type, name, load) when type in [:attribute, :calculation] do {attr_type, constraints} = if type == :calculation do calc = Map.get(query.calculations, name) {calc.type, calc.constraints} else attr = Ash.Resource.Info.attribute(query.resource, name) {attr.type, attr.constraints} end case Ash.Type.merge_load( attr_type, query.load_through[type][name] || [], load, constraints, nil ) do {:ok, new_value} -> Map.update!(query, :load_through, fn types -> types |> Map.put_new(type, %{}) |> Map.update!(type, fn load_through -> Map.put(load_through, name, new_value) end) end) {:error, error} -> Ash.Query.add_error(query, error) :error -> Ash.Query.add_error(query, "Type #{type} has no exported function merge_load/4") end end @doc """ Merges two query's load statements, for the purpose of handling calculation requirements. This should only be used if you are writing a custom type that is loadable. See the callback documentation for `c:Ash.Type.merge_load/4` for more. """ def merge_query_load(left, right, context) do if context do Ash.Actions.Read.Calculations.merge_query_load( left, right, context.domain, context[:calc_path], context[:calc_name], context[:calc_load], context[:relationship_path], :error, context[:strict_loads?], context[:reuse_values?], context[:authorize?] ) else load(left, right) end end @doc """ Loads relationships, calculations, or aggregates on the resource. By default, loading attributes has no effect, as all attributes are returned. See the section below on "Strict Loading" for more. ## Examples # Load simple relationships iex> Ash.Query.load(MyApp.Post, :author) %Ash.Query{load: [author: []], ...} # Load nested relationships iex> Ash.Query.load(MyApp.Post, [comments: [:author, :ratings]]) %Ash.Query{load: [comments: [author: [], ratings: []]], ...} # Load relationships with custom queries iex> author_query = Ash.Query.filter(MyApp.User, active: true) iex> Ash.Query.load(MyApp.Post, [comments: [author: author_query]]) %Ash.Query{load: [comments: [author: %Ash.Query{...}]], ...} # Load calculations with arguments iex> Ash.Query.load(MyApp.User, full_name: %{format: :last_first}) %Ash.Query{calculations: %{full_name: %Ash.Query.Calculation{...}}, ...} ## Strict Loading By passing `strict?: true`, only specified attributes will be loaded when passing a list of fields to fetch on a relationship, which allows for more optimized data-fetching. # Only load specific fields on relationships iex> Ash.Query.load(MyApp.Category, [:name, posts: [:title, :published_at]], strict?: true) %Ash.Query{load: [posts: [:title, :published_at]], ...} When using `strict?: true` and loading nested relationships, you must specify all the attributes you want to load alongside the nested relationships: # Must include needed attributes when loading nested relationships strictly iex> Ash.Query.load(MyApp.Post, [:title, :published_at, category: [:name]], strict?: true) %Ash.Query{...} ## See also - `select/3` for controlling which attributes are returned - `ensure_selected/2` for ensuring specific fields are selected - `Ash.read/2` for executing queries with loaded data - [Relationships Guide](/documentation/topics/resources/relationships.md) for understanding relationships - [Calculations Guide](/documentation/topics/resources/calculations.md) for understanding calculations """ @spec load( t() | Ash.Resource.t(), atom | Ash.Query.Calculation.t() | Ash.Query.Aggregate.t() | list(atom | Ash.Query.Calculation.t() | Ash.Query.Aggregate.t()) | list({atom | Ash.Query.Calculation.t() | Ash.Query.Aggregate.t(), term}), Keyword.t() ) :: t() def load(query, load_statement, opts \\ []) def load(query, %Ash.Query{} = new, opts) do query |> new() |> merge_load(new, opts) end def load(query, fields, opts) when not is_list(fields) do load(query, List.wrap(fields), opts) end def load(query, fields, opts) do query = new(query) Enum.reduce(fields, query, fn %Ash.Query{} = new, query -> merge_load(new, query, opts) [], query -> query {field, %__MODULE__{} = nested}, query -> if rel = Ash.Resource.Info.relationship(query.resource, field) do load_relationship(query, rel, nested, opts) else add_error( query, :load, Ash.Error.Query.InvalidLoad.exception(load: [{field, nested}]) ) end {field, {args, load_through}}, query -> if resource_calculation = Ash.Resource.Info.calculation(query.resource, field) do load_resource_calculation(query, resource_calculation, args, load_through) else add_error( query, :load, Ash.Error.Query.InvalidLoad.exception(load: [{field, {args, load_through}}]) ) end {field, rest}, query -> cond do rel = Ash.Resource.Info.relationship(query.resource, field) -> load_relationship(query, rel, rest, opts) resource_calculation = Ash.Resource.Info.calculation(query.resource, field) -> load_resource_calculation(query, resource_calculation, rest) attribute = Ash.Resource.Info.attribute(query.resource, field) -> if Ash.Type.can_load?(attribute.type, attribute.constraints) do query |> Ash.Query.ensure_selected(attribute.name) |> Ash.Query.load_through(:attribute, attribute.name, rest) else add_error( query, :load, Ash.Error.Query.InvalidLoad.exception(load: [{field, rest}]) ) end true -> add_error(query, :load, Ash.Error.Query.InvalidLoad.exception(load: field)) end field, query -> do_load(query, field, opts) end) end defp load_resource_calculation(query, resource_calculation, args, load_through \\ nil) do if Keyword.keyword?(args) || is_map(args) do {name, load} = cond do Keyword.keyword?(args) -> case Keyword.fetch(args, :as) do {:ok, value} -> {value, nil} :error -> if resource_calculation.field? do {resource_calculation.name, resource_calculation.name} else {resource_calculation.name, nil} end end is_map(args) -> case Map.fetch(args, :as) do {:ok, value} -> {value, nil} :error -> if resource_calculation.field? do {resource_calculation.name, resource_calculation.name} else {resource_calculation.name, nil} end end true -> if resource_calculation.field? do {resource_calculation.name, resource_calculation.name} else {resource_calculation.name, nil} end end case Calculation.from_resource_calculation(query.resource, resource_calculation, args: Map.new(args), source_context: query.context ) do {:ok, calculation} -> calculation = select_and_load_calc( resource_calculation, %{calculation | load: load, name: name, calc_name: resource_calculation.name}, query ) query = Map.update!(query, :calculations, &Map.put(&1, name, calculation)) if load_through do load_through(query, :calculation, name, load_through) else query end {:error, error} -> add_error(query, :load, error) end else add_error( query, Ash.Error.Query.InvalidLoad.exception(load: {resource_calculation.name, args}) ) end end @doc false def select_and_load_calc(resource_calculation, calculation, query) do module = calculation.module opts = calculation.opts if resource_calculation do resource_calculation_load = List.wrap(resource_calculation.load) loads = Ash.Resource.Calculation.load( module, query, opts, Map.put(calculation.context, :context, query.context) ) |> Ash.Actions.Helpers.validate_calculation_load!(module) |> Enum.concat(resource_calculation_load) %{calculation | required_loads: loads} else loads = Ash.Resource.Calculation.load( module, query, opts, Map.put(calculation.context, :context, query.context) ) |> Ash.Actions.Helpers.validate_calculation_load!(module) %{ calculation | required_loads: Enum.concat(List.wrap(loads), List.wrap(calculation.required_loads)) } end end defp fetch_key(map, key) when is_map(map) do Map.fetch(map, key) end defp fetch_key(keyword, key) do if Keyword.keyword?(keyword) do Keyword.fetch(keyword, key) else :error end end @doc false def resource_calc_to_calc(query, name, resource_calculation, args \\ %{}) do {name, load} = case fetch_key(args, :as) do :error -> {name, name} {:ok, key} -> {key, nil} end with {:ok, calculation} <- Ash.Query.Calculation.from_resource_calculation(query.resource, resource_calculation, source_context: query.context, args: Map.new(args) ) do {:ok, select_and_load_calc( resource_calculation, %{calculation | load: load, name: name}, query )} end end defp do_load(query, field, opts) when is_list(field) do Enum.reduce(field, query, &do_load(&2, &1, opts)) end defp do_load(query, field, opts) do cond do match?(%Ash.Query.Calculation{}, field) -> Map.update!( query, :calculations, &Map.put( &1, field.name, select_and_load_calc(nil, field, query) ) ) match?(%{__struct__: Ash.Query.Aggregate}, field) -> if Ash.DataLayer.data_layer_can?(query.resource, {:aggregate, field.kind}) do Map.update!( query, :aggregates, &Map.put( &1, field.name, field ) ) else add_error( query, Ash.Error.Query.AggregatesNotSupported.exception( resource: query.resource, feature: "using" ) ) end is_atom(field) && Ash.Resource.Info.attribute(query.resource, field) -> ensure_selected(query, field) rel = Ash.Resource.Info.relationship(query.resource, field) -> load_relationship(query, rel, [], opts) aggregate = Ash.Resource.Info.aggregate(query.resource, field) -> can_do_aggregate? = if Map.get(aggregate, :related?, true) do Ash.DataLayer.data_layer_can?(query.resource, {:aggregate, aggregate.kind}) else Ash.DataLayer.data_layer_can?(query.resource, {:aggregate, aggregate.kind}) && Ash.DataLayer.data_layer_can?(query.resource, {:aggregate, :unrelated}) end with {:can?, true} <- {:can?, can_do_aggregate?}, {:ok, query_aggregate} <- Aggregate.new( query.resource, aggregate.name, aggregate.kind, agg_name: aggregate.name, path: aggregate.relationship_path, query: [filter: aggregate.filter, sort: aggregate.sort], field: aggregate.field, default: aggregate.default, filterable?: aggregate.filterable?, type: aggregate.type, constraints: aggregate.constraints, implementation: aggregate.implementation, include_nil?: aggregate.include_nil?, uniq?: aggregate.uniq?, read_action: aggregate.read_action, authorize?: aggregate.authorize?, sortable?: aggregate.sortable?, sensitive?: aggregate.sensitive?, multitenancy: aggregate.multitenancy, join_filters: Map.new(aggregate.join_filters, &{&1.relationship_path, &1.filter}), resource: aggregate.resource, related?: Map.get(aggregate, :related?, true) ) do query_aggregate = %{query_aggregate | load: field} new_aggregates = Map.put(query.aggregates, aggregate.name, query_aggregate) %{query | aggregates: new_aggregates} else {:error, error} -> add_error( query, :aggregates, Ash.Error.to_ash_error(error, nil, bread_crumbs: "Loading aggregate: #{inspect(field)} for query: #{inspect(query)}" ) ) {:can?, false} -> add_error( query, :aggregate, AggregatesNotSupported.exception(resource: query.resource, feature: "using") ) end resource_calculation = Ash.Resource.Info.calculation(query.resource, field) -> load_resource_calculation(query, resource_calculation, %{}) true -> add_error(query, :load, Ash.Error.Query.InvalidLoad.exception(load: field)) end end @doc false def validate_calculation_arguments(calculation, args, allow_expr? \\ true) do args = if Keyword.keyword?(args) do Map.new(args) else args end args = Map.delete(args, :as) has_one_expr? = Enum.any?(args, fn {_, value} -> Ash.Expr.expr?(value) end) args |> Enum.reduce_while({:ok, %{}}, fn {key, value}, {:ok, arg_values} -> argument = if is_binary(key) do Enum.find(calculation.arguments, fn arg -> to_string(arg.name) == key end) else Enum.find(calculation.arguments, fn arg -> arg.name == key end) end value = Ash.Type.Helpers.handle_indexed_maps(argument.type, value) cond do !argument -> error_calc = case calculation do %{calc_name: calc_name} -> calc_name %Ash.Resource.Calculation{name: name} -> name calc -> calc end {:halt, {:error, Ash.Error.Invalid.NoSuchInput.exception( calculation: error_calc, input: key, inputs: Enum.map(calculation.arguments, & &1.name) )}} Ash.Expr.expr?(value) && argument.allow_expr? && allow_expr? -> {:cont, {:ok, Map.put( arg_values, argument.name, %Ash.Query.Function.Type{ arguments: [value, argument.type, argument.constraints] } )}} Ash.Expr.expr?(value) -> {:halt, {:error, InvalidCalculationArgument.exception( field: argument.name, calculation: calculation.name, message: "does not support expressions", value: value )}} is_nil(value) && argument.allow_nil? -> {:cont, {:ok, Map.put(arg_values, argument.name, nil)}} is_nil(value) && is_nil(argument.default) -> {:halt, {:error, InvalidCalculationArgument.exception( field: argument.name, calculation: calculation.name, message: "is required", value: value )}} is_nil(Map.get(args, argument.name, Map.get(args, to_string(argument.name)))) && not is_nil(value) -> if has_one_expr? do {:cont, {:ok, Map.put( arg_values, argument.name, %Ash.Query.Function.Type{ arguments: [value, argument.type, argument.constraints] } )}} else {:cont, {:ok, Map.put( arg_values, argument.name, value )}} end true -> with {:ok, casted} <- Ash.Type.cast_input(argument.type, value, argument.constraints), {:ok, casted} <- Ash.Type.apply_constraints(argument.type, casted, argument.constraints) do if has_one_expr? do {:cont, {:ok, Map.put( arg_values, argument.name, %Ash.Query.Function.Type{ arguments: [value, argument.type, argument.constraints] } )}} else cond do is_nil(casted) && argument.allow_nil? -> {:cont, {:ok, Map.put(arg_values, argument.name, nil)}} is_nil(casted) && is_nil(argument.default) -> {:halt, {:error, InvalidCalculationArgument.exception( field: argument.name, calculation: calculation.name, message: "is required", value: value )}} is_nil(Map.get(args, argument.name, Map.get(args, to_string(argument.name)))) && not is_nil(value) -> {:cont, {:ok, Map.put( arg_values, argument.name, value )}} true -> {:cont, {:ok, Map.put(arg_values, argument.name, casted)}} end end else {:error, error} when is_binary(error) -> {:halt, {:error, InvalidCalculationArgument.exception( field: argument.name, calculation: calculation.name, message: error, value: value )}} {:error, error} -> {:halt, {:error, Ash.Error.to_ash_error(error)}} end end end) |> set_defaults(calculation) end defp set_defaults({:ok, inputs}, calculation) do Enum.reduce_while(calculation.arguments, {:ok, inputs}, fn argument, {:ok, inputs} -> value = case Map.fetch(inputs, argument.name) do :error -> Map.fetch(inputs, to_string(argument.name)) {:ok, value} -> {:ok, value} end case value do {:ok, value} -> if is_nil(value) && !argument.allow_nil? do {:halt, {:error, InvalidCalculationArgument.exception( field: argument.name, calculation: calculation.name, message: "is required", value: nil )}} else {:cont, {:ok, inputs}} end :error -> value = calc_arg_default(argument.default) if is_nil(value) && !argument.allow_nil? do {:halt, {:error, InvalidCalculationArgument.exception( field: argument.name, calculation: calculation.name, message: "is required", value: value )}} else {:cont, {:ok, Map.put(inputs, argument.name, value)}} end end end) end defp set_defaults(inputs, _), do: inputs defp calc_arg_default({module, function, args}), do: apply(module, function, args) defp calc_arg_default(value) when is_function(value, 0), do: value.() defp calc_arg_default(value), do: value @doc """ Sets a specific context key to a specific value. Context is used to pass additional information through the query pipeline that can be accessed by preparations, calculations, and other query logic. This function adds or updates a single key in the query's context map. ## Examples # Add actor information to context iex> query = MyApp.Post |> Ash.Query.put_context(:actor, current_user) %Ash.Query{context: %{actor: %User{...}}, ...} # Add custom metadata for preparations iex> query = MyApp.Post |> Ash.Query.put_context(:source, "api") %Ash.Query{context: %{source: "api"}, ...} # Chain multiple context additions iex> MyApp.Post ...> |> Ash.Query.put_context(:tenant, "org_123") ...> |> Ash.Query.put_context(:locale, "en_US") %Ash.Query{context: %{tenant: "org_123", locale: "en_US"}, ...} ## See also - `set_context/2` for setting the entire context map - `for_read/4` for passing context when creating queries - Preparations and calculations can access context for custom logic """ @spec put_context(t() | Ash.Resource.t(), atom, term) :: t() def put_context(query, key, value) do query = new(query) set_context(query, %{key => value}) end @doc """ Set the result of the action. This will prevent running the underlying datalayer behavior """ @spec set_result(t(), term) :: t() def set_result(query, result) do set_context(query, %{private: %{action_result: result}}) end @doc """ Removes a result set previously with `set_result/2` """ @spec clear_result(t()) :: t() def clear_result(query) do %{ query | context: Map.update(query.context, :private, %{}, &Map.delete(&1, :action_result)) } end @doc """ Merge a map of values into the query context """ @spec set_context(t() | Ash.Resource.t(), map | nil) :: t() def set_context(query, nil), do: new(query) def set_context(query, map) do query = new(query) %{ query | context: query.context |> Ash.Helpers.deep_merge_maps(map) |> then(&Ash.Helpers.deep_merge_maps(&1, map[:shared] || %{})) } end @doc """ Gets the value of an argument provided to the query. Returns the argument value if found, or `nil` if not found. Arguments can be provided when creating queries with `for_read/4` and are used by action logic such as preparations and filters. ## Examples # Get an argument that exists iex> query = Ash.Query.for_read(MyApp.Post, :published, %{since: ~D[2023-01-01]}) iex> Ash.Query.get_argument(query, :since) ~D[2023-01-01] # Get an argument that doesn't exist iex> query = Ash.Query.for_read(MyApp.Post, :published, %{}) iex> Ash.Query.get_argument(query, :since) nil # Arguments can be accessed by string or atom key iex> query = Ash.Query.for_read(MyApp.Post, :search, %{"query" => "elixir"}) iex> Ash.Query.get_argument(query, :query) "elixir" ## See also - `fetch_argument/2` for safer argument access with explicit error handling - `set_argument/3` for adding arguments to queries - `for_read/4` for creating queries with arguments """ @spec get_argument(t, atom | String.t()) :: term def get_argument(query, argument) when is_atom(argument) or is_binary(argument) do case fetch_argument(query, argument) do {:ok, value} -> value :error -> nil end end @doc """ Fetches the value of an argument provided to the query. Returns `{:ok, value}` if the argument exists, or `:error` if not found. This is the safer alternative to `get_argument/2` when you need to distinguish between a `nil` value and a missing argument. ## Examples # Fetch an argument that exists iex> query = Ash.Query.for_read(MyApp.Post, :published, %{since: ~D[2023-01-01]}) iex> Ash.Query.fetch_argument(query, :since) {:ok, ~D[2023-01-01]} # Fetch an argument that doesn't exist iex> query = Ash.Query.for_read(MyApp.Post, :published, %{}) iex> Ash.Query.fetch_argument(query, :since) :error # Distinguish between nil and missing arguments iex> query = Ash.Query.for_read(MyApp.Post, :search, %{query: nil}) iex> Ash.Query.fetch_argument(query, :query) {:ok, nil} ## See also - `get_argument/2` for simpler argument access - `set_argument/3` for adding arguments to queries - `for_read/4` for creating queries with arguments """ @spec fetch_argument(t, atom | String.t()) :: {:ok, term} | :error def fetch_argument(query, argument) when is_atom(argument) or is_binary(argument) do query = new(query) case Map.fetch(query.arguments, argument) do {:ok, value} -> {:ok, value} :error -> case Map.fetch(query.arguments, to_string(argument)) do {:ok, value} -> {:ok, value} :error -> :error end end end @doc """ Adds an argument to the query. Arguments are used by action logic such as preparations, filters, and other query modifications. They become available in filter templates and can be referenced in action configurations. Setting an argument after a query has been validated for an action will result in an error. ## Examples # Set an argument for use in action filters iex> query = Ash.Query.new(MyApp.Post) iex> Ash.Query.set_argument(query, :author_id, 123) %Ash.Query{arguments: %{author_id: 123}, ...} # Set multiple arguments by chaining iex> MyApp.Post ...> |> Ash.Query.set_argument(:category, "tech") ...> |> Ash.Query.set_argument(:published, true) %Ash.Query{arguments: %{category: "tech", published: true}, ...} # Arguments are used in action preparations and filters iex> query = MyApp.Post ...> |> Ash.Query.for_read(:by_author, %{author_id: 123}) ...> |> Ash.Query.set_argument(:include_drafts, false) %Ash.Query{arguments: %{author_id: 123, include_drafts: false}, ...} ## See also - `get_argument/2` for retrieving argument values - `fetch_argument/2` for safe argument retrieval - `for_read/4` for creating queries with initial arguments """ def set_argument(query, argument, value) do maybe_already_validated_error!(query) query = new(query) if query.action do argument = Enum.find( query.action.arguments, &(&1.name == argument || to_string(&1.name) == argument) ) with {:arg, argument} when not is_nil(argument) <- {:arg, argument}, value <- Ash.Type.Helpers.handle_indexed_maps(argument.type, value), constraints <- Ash.Type.include_source(argument.type, query, argument.constraints), {:ok, casted} <- Ash.Type.cast_input(argument.type, value, constraints), {:constrained, {:ok, casted}, argument} when not is_nil(casted) <- {:constrained, Ash.Type.apply_constraints(argument.type, casted, constraints), argument} do %{query | arguments: Map.put(query.arguments, argument.name, casted)} else {:arg, nil} -> query {:constrained, {:ok, nil}, argument} -> %{query | arguments: Map.put(query.arguments, argument.name, nil)} {:constrained, {:error, error}, argument} -> query = %{query | arguments: Map.put(query.arguments, argument.name, value)} add_invalid_errors(value, query, argument, error) {:error, error} -> query = %{query | arguments: Map.put(query.arguments, argument.name, value)} add_invalid_errors(value, query, argument, error) :error -> query = %{query | arguments: Map.put(query.arguments, argument.name, value)} add_invalid_errors(value, query, argument, "is invalid") end else %{query | arguments: Map.put(query.arguments, argument, value)} end end defp reset_arguments(%{arguments: arguments} = query) do Enum.reduce(arguments, query, fn {key, value}, query -> set_argument(query, key, value) end) end defp add_invalid_errors(value, query, argument, error) do query = %{query | invalid_keys: MapSet.put(query.invalid_keys, argument.name)} messages = if Keyword.keyword?(error) do [error] else List.wrap(error) end messages |> Enum.reduce(query, fn message, query -> message |> Ash.Type.Helpers.error_to_exception_opts(argument) |> Enum.reduce(query, fn opts, query -> add_error( query, InvalidArgument.exception( value: value, field: Keyword.get(opts, :field), message: Keyword.get(opts, :message), vars: opts ) ) end) end) end @doc """ Remove an argument from the query """ def delete_argument(query, argument_or_arguments) do query = new(query) argument_or_arguments |> List.wrap() |> Enum.reduce(query, fn argument, query -> %{query | arguments: Map.delete(query.arguments, argument)} end) end @doc """ Merge a map of arguments to the arguments list """ def set_arguments(query, map) do query = new(query) %{query | arguments: Map.merge(query.arguments, map)} end defp argument_default(value) when is_function(value, 0), do: value.() defp argument_default(value), do: value @doc """ Sets the tenant for the query. In multitenant applications, this function configures which tenant's data the query should operate on. The tenant value is used to filter data and ensure proper data isolation between tenants. ## Examples # Set tenant using a string identifier iex> MyApp.Post |> Ash.Query.set_tenant("org_123") %Ash.Query{tenant: "org_123", ...} # Set tenant using a struct that implements Ash.ToTenant iex> org = %MyApp.Organization{id: 456} iex> MyApp.Post |> Ash.Query.set_tenant(org) %Ash.Query{tenant: %MyApp.Organization{id: 456}, ...} # Use with other query functions iex> MyApp.Post ...> |> Ash.Query.set_tenant("org_123") ...> |> Ash.Query.filter(published: true) %Ash.Query{tenant: "org_123", ...} ## See also - `for_read/4` for setting tenant when creating queries - `Ash.ToTenant` protocol for custom tenant conversion - `put_context/3` for adding tenant to query context """ @spec set_tenant(t() | Ash.Resource.t(), Ash.ToTenant.t()) :: t() def set_tenant(query, tenant) do query = new(query) %{query | tenant: tenant, to_tenant: Ash.ToTenant.to_tenant(tenant, query.resource)} end @doc """ Sets the pagination options of the query. This function configures how results should be paginated when the query is executed. Ash supports both offset-based pagination (limit/offset) and keyset-based pagination (cursor-based), with keyset being more efficient for large datasets. ## Examples # Offset-based pagination (page 2, 10 items per page) iex> MyApp.Post ...> |> Ash.Query.page(limit: 10, offset: 10) %Ash.Query{page: [limit: 10, offset: 10], ...} # Keyset pagination with before/after cursors iex> MyApp.Post ...> |> Ash.Query.sort(:created_at) ...> |> Ash.Query.page(limit: 20, after: "cursor_string") %Ash.Query{page: [limit: 20, after: "cursor_string"], ...} # Disable pagination (return all results) iex> MyApp.Post |> Ash.Query.page(nil) %Ash.Query{page: nil, ...} # Pagination with counting iex> MyApp.Post |> Ash.Query.page(limit: 10, count: true) %Ash.Query{page: [limit: 10, count: true], ...} ## Pagination Types ### Limit/offset pagination #{Spark.Options.docs(Ash.Page.Offset.page_opts())} ### Keyset pagination #{Spark.Options.docs(Ash.Page.Keyset.page_opts())} ## See also - `limit/2` and `offset/2` for simple pagination without page metadata - `sort/3` for ordering results (required for keyset pagination) - `Ash.read/2` for executing paginated queries """ @spec page(t() | Ash.Resource.t(), Keyword.t() | nil | false) :: t() def page(query, page_opts) do query = new(query) case Ash.Page.page_opts(page_opts) do {:ok, page_opts} -> %{query | page: page_opts} {:error, _error} -> add_error(query, :page, InvalidPage.exception(page: page_opts)) end end @doc "Removes a field from the list of fields to load" @spec unload(t(), list(atom)) :: t() def unload(query, fields) do query = new(query) Enum.reduce(fields, query, fn field, query -> case field do {field, rest} -> new_loads = do_unload_load(query.load, {field, rest}) %{query | load: new_loads} field -> do_unload(query, field) end end) end defp do_unload(query, field) do cond do Ash.Resource.Info.attribute(query.resource, field) -> query Ash.Resource.Info.relationship(query.resource, field) -> %{query | load: Keyword.delete(query.load, field)} Ash.Resource.Info.aggregate(query.resource, field) -> new_aggregates = Enum.reduce(query.aggregates, %{}, fn {_field, %{load: ^field}}, acc -> acc {field, aggregate}, acc -> Map.put(acc, field, aggregate) end) %{query | aggregates: new_aggregates} Ash.Resource.Info.calculation(query.resource, field) -> new_calculations = Enum.reduce(query.calculations, %{}, fn {_field, %{load: ^field}}, acc -> acc {field, calculation}, acc -> Map.put(acc, field, calculation) end) %{query | calculations: new_calculations} true -> query |> Map.update!(:calculations, &Map.delete(&1, field)) |> Map.update!(:aggregates, &Map.delete(&1, field)) end end defp do_unload_load(%__MODULE__{} = query, unload) do %{query | load: do_unload_load(query.load, unload)} end defp do_unload_load(loads, {field, rest}) do Enum.reduce(loads, [], fn ^field, acc -> acc {^field, value}, acc -> new_value = rest |> List.wrap() |> Enum.reduce(value, &do_unload_load(&2, &1)) [{field, new_value} | acc] value, acc -> [value | acc] end) |> Enum.reverse() end defp do_unload_load(loads, field) do do_unload_load(loads, {field, []}) end @build_opts [ filter: [ type: :any, doc: "A filter keyword, map or expression" ], filter_input: [ type: :any, doc: "A filter keyword or map, provided as input from an external source" ], sort: [ type: :any, doc: "A sort list or keyword" ], sort_input: [ type: :any, doc: "A sort list or keyword, provided as input from an external source" ], default_sort: [ type: :any, doc: "A sort list or keyword to apply only if no other sort is specified, So if you apply any `sort`, this will be ignored." ], distinct_sort: [ type: :any, doc: "A distinct_sort list or keyword" ], limit: [ type: :integer, doc: "A limit to apply" ], offset: [ type: :integer, doc: "An offset to apply" ], load: [ type: :any, doc: "A load statement to add to the query" ], strict_load: [ type: :any, doc: "A load statement to add to the query with the `strict?` option set to `true`" ], select: [ type: :any, doc: "A select statement to add to the query" ], ensure_selected: [ type: :any, doc: "An ensure_selected statement to add to the query" ], aggregate: [ type: :any, doc: "A custom aggregate to add to the query. Can be `{name, type, relationship}` or `{name, type, relationship, build_opts}`" ], calculate: [ type: :any, doc: "A custom calculation to add to the query. Can be `{name, module_and_opts}` or `{name, module_and_opts, context}`" ], distinct: [ type: {:list, :atom}, doc: "A distinct clause to add to the query" ], context: [ type: :map, doc: "A map to merge into the query context" ] ] @doc false def build_opts, do: @build_opts @doc """ Builds a query from a keyword list. This is used by certain query constructs like aggregates. It can also be used to manipulate a data structure before passing it to an ash query. It allows for building an entire query struct using only a keyword list. For example: ```elixir Ash.Query.build(MyResource, filter: [name: "fred"], sort: [name: :asc], load: [:foo, :bar], offset: 10) ``` If you want to use the expression style filters, you can use `expr/1`. For example: ```elixir import Ash.Expr, only: [expr: 1] Ash.Query.build(Myresource, filter: expr(name == "marge")) ``` ## Options #{Spark.Options.docs(@build_opts)} """ @spec build(Ash.Resource.t() | t(), Ash.Domain.t() | nil, Keyword.t()) :: t() @spec build(Ash.Resource.t() | t(), Keyword.t()) :: t() def build(resource, domain \\ nil, keyword) do query = resource |> new() |> then(fn query -> if domain do set_domain(query, domain) else query end end) Enum.reduce(keyword, query, fn {:filter, value}, query -> do_filter(query, value) {:filter_input, value}, query -> filter_input(query, value) {:sort, value}, query -> sort(query, value) {:sort_input, value}, query -> sort_input(query, value) {:default_sort, value}, query -> default_sort(query, value) {:distinct_sort, value}, query -> distinct_sort(query, value) {:limit, value}, query -> limit(query, value) {:offset, value}, query -> offset(query, value) {:load, value}, query -> load(query, value) {:strict_load, value}, query -> load(query, value, strict?: true) {:distinct, value}, query -> distinct(query, value) {:lock, lock_type}, query -> lock(query, lock_type) {:aggregate, {name, type, relationship}}, query -> aggregate(query, name, type, relationship) {:aggregate, {name, type, relationship, agg_query}}, query -> aggregate(query, name, type, relationship, agg_query) {:calculate, {name, type, module_and_opts}}, query -> calculate(query, name, type, module_and_opts) {:calculate, {name, type, module_and_opts, arguments}}, query -> calculate(query, name, type, module_and_opts, arguments) {:select, fields}, query -> select(query, fields) {:deselect, fields}, query -> deselect(query, fields) {:ensure_selected, fields}, query -> ensure_selected(query, fields) {:context, context}, query -> set_context(query, context) end) end @doc "Set the query's domain, and any loaded query's domain" def set_domain(query, domain) do query = new(query) %{query | domain: domain, load: set_load_domain(query.load, domain)} end @doc """ Adds an aggregation to the query. Aggregations are made available on the `aggregates` field of the records returned. They allow you to compute values from related data without loading entire relationships, making them very efficient for statistical operations. ## Examples # Count related records iex> Ash.Query.aggregate(MyApp.Author, :post_count, :count, :posts) %Ash.Query{aggregates: %{post_count: %Ash.Query.Aggregate{...}}, ...} # Sum values from related records iex> Ash.Query.aggregate(MyApp.Author, :total_likes, :sum, :posts, field: :like_count) %Ash.Query{aggregates: %{total_likes: %Ash.Query.Aggregate{...}}, ...} # Average with filtered aggregation iex> published_query = Ash.Query.filter(MyApp.Post, published: true) iex> Ash.Query.aggregate(MyApp.Author, :avg_published_likes, :avg, :posts, ...> field: :like_count, query: published_query) %Ash.Query{aggregates: %{avg_published_likes: %Ash.Query.Aggregate{...}}, ...} # Count with default value iex> Ash.Query.aggregate(MyApp.Author, :post_count, :count, :posts, default: 0) %Ash.Query{aggregates: %{post_count: %Ash.Query.Aggregate{...}}, ...} ## Options * `query` - The query over the destination resource to use as a base for aggregation * `field` - The field to use for the aggregate. Not necessary for all aggregate types * `default` - The default value to use if the aggregate returns nil * `filterable?` - Whether or not this aggregate may be referenced in filters * `type` - The type of the aggregate * `constraints` - Type constraints for the aggregate's type * `implementation` - An implementation used when the aggregate kind is custom * `read_action` - The read action to use on the destination resource * `authorize?` - Whether or not to authorize access to this aggregate * `join_filters` - A map of relationship paths to filter expressions ## See also - [Resource DSL aggregates documentation](dsl-ash-resource.html#aggregates) for more information - `load/3` for loading relationships instead of aggregating - `calculate/8` for custom calculations - `Ash.read/2` for executing queries with aggregates """ @spec aggregate(t() | Ash.Resource.t(), atom() | String.t(), atom(), atom()) :: t() def aggregate(query, name, kind, relationship) do aggregate(query, name, kind, relationship, []) end @spec aggregate(t() | Ash.Resource.t(), atom() | String.t(), atom(), atom(), Keyword.t()) :: t() def aggregate(query, name, kind, relationship, opts) when is_list(opts) do agg_query = opts[:query] default = opts[:default] filterable? = Keyword.get(opts, :filterable?, true) sortable? = Keyword.get(opts, :filterable?, true) type = opts[:type] constraints = opts[:constraints] || [] implementation = opts[:implementation] include_nil? = Keyword.get(opts, :include_nil?, false) uniq? = opts[:uniq?] read_action = opts[:read_action] authorize? = Keyword.get(opts, :authorize?, true) join_filters = Keyword.get(opts, :join_filters, %{}) sensitive? = Keyword.get(opts, :sensitive?, false) {field, agg_query} = case agg_query do %Ash.Query{} = query -> {opts[:field], query} agg_query -> Keyword.pop(agg_query || [], :field, opts[:field]) end query = new(query) relationship = List.wrap(relationship) {related, actual_relationship, opts_with_resource, is_unrelated?} = case relationship do [module] when is_atom(module) -> if function_exported?(module, :__info__, 1) do {module, [], Keyword.put(opts, :resource, module), true} else related = Ash.Resource.Info.related(query.resource, relationship) {related, relationship, opts, false} end _ -> # Regular relationship path related = Ash.Resource.Info.related(query.resource, relationship) {related, relationship, opts, false} end # Check data layer capabilities can_do_aggregate? = if is_unrelated? do Ash.DataLayer.data_layer_can?(query.resource, {:aggregate, kind}) && Ash.DataLayer.data_layer_can?(query.resource, {:aggregate, :unrelated}) else # For related aggregates, just check the aggregate kind Ash.DataLayer.data_layer_can?(query.resource, {:aggregate, kind}) end if can_do_aggregate? do agg_query = case agg_query do [] -> read_action = Ash.Resource.Info.primary_action!(related, :read).name related |> for_read(read_action) options when is_list(options) -> read_action = Ash.Resource.Info.primary_action!(related, :read).name related |> for_read(read_action) |> Ash.Query.Aggregate.build_query(query.resource, options) %Ash.Query{} = query -> query end case Aggregate.new( query.resource, name, kind, Keyword.merge( [ path: actual_relationship, query: agg_query, field: field, default: default, filterable?: filterable?, sortable?: sortable?, sensitive?: sensitive?, include_nil?: include_nil?, type: type, constraints: constraints, implementation: implementation, uniq?: uniq?, read_action: read_action, authorize?: authorize?, join_filters: join_filters ], opts_with_resource ) ) do {:ok, aggregate} -> new_aggregates = Map.put(query.aggregates, aggregate.name, aggregate) %{query | aggregates: new_aggregates} {:error, error} -> add_error(query, :aggregate, error) end else add_error( query, :aggregate, AggregatesNotSupported.exception(resource: query.resource, feature: "using #{kind}") ) end end @doc """ Adds a calculation to the query. Calculations are made available on the `calculations` field of the records returned. They allow you to compute dynamic values based on record data, other fields, or external information at query time. The `module_and_opts` argument accepts either a `module` or a `{module, opts}`. For more information on what that module should look like, see `Ash.Resource.Calculation`. ## Examples # Add a simple calculation iex> Ash.Query.calculate(MyApp.User, :display_name, :string, ...> {MyApp.Calculations.DisplayName, []}) %Ash.Query{calculations: %{display_name: %{...}}, ...} # Add calculation with arguments iex> Ash.Query.calculate(MyApp.Post, :word_count, :integer, ...> {MyApp.Calculations.WordCount, []}, %{field: :content}) %Ash.Query{calculations: %{word_count: %{...}}, ...} # Add calculation with constraints and context iex> Ash.Query.calculate(MyApp.Product, :discounted_price, :decimal, ...> {MyApp.Calculations.Discount, []}, %{rate: 0.1}, ...> [precision: 2, scale: 2], %{currency: "USD"}) %Ash.Query{calculations: %{discounted_price: %{...}}, ...} ## See also - `Ash.Resource.Calculation` for implementing custom calculations - `aggregate/5` for computing values from related records - `load/3` for loading predefined calculations from the resource - `select/3` for controlling which fields are returned alongside calculations """ @spec calculate( t() | Ash.Resource.t(), term(), Ash.Type.t(), module() | {module(), Keyword.t()}, map(), Keyword.t(), map(), Keyword.t() ) :: t() def calculate( query, name, type, module_and_opts, arguments \\ %{}, constraints \\ [], extra_context \\ %{}, new_calculation_opts \\ [] ) do query = new(query) {module, opts} = case module_and_opts do {module, opts} -> if Ash.Expr.expr?({module, opts}) do {Ash.Resource.Calculation.Expression, expr: {module, opts}} else {module, opts} end module when is_atom(module) -> {module, []} value -> {Ash.Resource.Calculation.Expression, expr: value} end case Calculation.new( name, module, opts, type, constraints, Keyword.merge( [arguments: arguments, source_context: query.context], new_calculation_opts ) ) do {:ok, calculation} -> context = %{ calculation.context | actor: Map.get(extra_context, :actor), tenant: Map.get(extra_context, :tenant), tracer: Map.get(extra_context, :tracer), authorize?: Map.get(extra_context, :authorize?) } calculation = %{calculation | context: context} loads = Ash.Resource.Calculation.load( module, query, opts, calculation.context ) |> Ash.Actions.Helpers.validate_calculation_load!(module) |> Enum.concat(List.wrap(calculation.required_loads)) calculation = %{calculation | required_loads: loads} %{query | calculations: Map.put(query.calculations, name, calculation)} {:error, error} -> add_error(query, :calculations, error) end end @doc """ Apply a sort only if no sort has been specified yet. This is useful for providing default sorts that can be overridden. ## Examples ```elixir # This will sort by name if no sort has been specified Ash.Query.default_sort(query, :name) # This will sort by name descending if no sort has been specified Ash.Query.default_sort(query, name: :desc) ``` """ @spec default_sort(t() | Ash.Resource.t(), Ash.Sort.t(), opts :: Keyword.t()) :: t() def default_sort(query, sorts, opts \\ []) do query = new(query) if query.sort == [] do sort(query, sorts, opts) else query end end @doc """ Adds a resource calculation to the query as a custom calculation with the provided name. Example: Ash.Query.load_calculation_as(query, :calculation, :some_name, args: %{}, load_through: [:foo]) """ def load_calculation_as(query, calc_name, as_name, opts_or_args \\ %{}, opts \\ []) do query = new(query) {args, opts} = if Keyword.keyword?(opts_or_args) do {opts_or_args[:args] || %{}, opts_or_args} else {opts_or_args, opts} end args = Map.put(args, :as, as_name) if resource_calculation = Ash.Resource.Info.calculation(query.resource, calc_name) do if opts[:load_through] do load_resource_calculation(query, resource_calculation, args) else load_resource_calculation(query, resource_calculation, args, opts[:load_through]) end else add_error(query, "No such calculation: #{inspect(calc_name)}") end end @doc """ Limits the number of results returned from the query. This function sets the maximum number of records that will be returned when the query is executed. Useful for pagination and preventing large result sets from consuming too much memory. ## Examples # Limit to 10 results iex> MyApp.Post |> Ash.Query.limit(10) %Ash.Query{limit: 10, ...} # Remove existing limit iex> query |> Ash.Query.limit(nil) %Ash.Query{limit: nil, ...} # Use with other query functions iex> MyApp.Post ...> |> Ash.Query.filter(published: true) ...> |> Ash.Query.sort(:created_at) ...> |> Ash.Query.limit(5) %Ash.Query{limit: 5, ...} ## See also - `offset/2` for skipping records (pagination) - `page/2` for keyset pagination - `sort/3` for ordering results before limiting """ @spec limit(t() | Ash.Resource.t(), nil | integer()) :: t() def limit(query, nil), do: new(query) def limit(query, limit) when is_integer(limit) do query = new(query) if Ash.DataLayer.data_layer_can?(query.resource, :limit) do query |> Map.put(:limit, max(0, limit)) else add_error(query, :limit, "Data layer does not support limits") end end def limit(query, limit) do add_error(query, :offset, InvalidLimit.exception(limit: limit)) end @doc """ Skips the first n records in the query results. This function is often used for offset-based pagination, allowing you to skip a specified number of records from the beginning of the result set. Often used together with `limit/2` to implement pagination. ## Examples # Skip the first 20 records iex> MyApp.Post |> Ash.Query.offset(20) %Ash.Query{offset: 20, ...} # Remove existing offset iex> query |> Ash.Query.offset(nil) %Ash.Query{offset: 0, ...} # Pagination example: page 3 with 10 items per page iex> MyApp.Post ...> |> Ash.Query.sort(:created_at) ...> |> Ash.Query.offset(20) # Skip first 20 (pages 1-2) ...> |> Ash.Query.limit(10) # Take next 10 (page 3) %Ash.Query{offset: 20, limit: 10, ...} ## See also - `limit/2` for limiting the number of results - `page/2` for keyset pagination (more efficient for large datasets) - `sort/3` for ordering results before offsetting """ @spec offset(t() | Ash.Resource.t(), nil | integer()) :: t() def offset(query, nil), do: new(query) def offset(query, offset) when is_integer(offset) do query = new(query) if Ash.DataLayer.data_layer_can?(query.resource, :offset) do query |> Map.put(:offset, max(0, offset)) else add_error(query, :offset, "Data layer does not support offset") end end def offset(query, offset) do query |> new() |> add_error(:offset, InvalidOffset.exception(offset: offset)) end defp load_relationship(query, rel, statement, opts) do loaded = Map.update!(query, :load, fn load -> if Keyword.has_key?(load, rel.name) do Keyword.update!(load, rel.name, &load(&1, statement, opts)) else query = case statement do %Ash.Query{} = statement -> statement statement -> query = if opts[:strict?] && statement not in [nil, []] do select(new(rel.destination), []) else new(rel.destination) end load(query, statement, opts) end Keyword.put(load, rel.name, query) end end) case loaded.load[rel.name] do %{errors: errors} when errors != [] -> add_error(loaded, :load, Enum.map(errors, &Ash.Error.set_path(&1, [rel.name]))) related_query -> if Map.get(rel, :manual) && (related_query.limit || (related_query.offset && related_query.offset != 0)) do add_error(loaded, :error, [ Ash.Error.Load.InvalidQuery.exception( resource: rel.source, relationship: rel.name, query: related_query ) ]) else loaded end end end @doc false def validate_load(query, loads, path \\ []) do case do_validate_load(query, loads, path) do [] -> :ok errors -> {:error, errors} end end defp do_validate_load(_query, %Ash.Query{} = load_query, path) do case load_query.errors do [] -> [] errors -> Enum.map(errors, &Ash.Error.set_path(&1, path)) end end defp do_validate_load(query, {atom, _} = tuple, path) when is_atom(atom) do do_validate_load(query, [tuple], path) end defp do_validate_load(query, loads, path) when is_list(loads) do query = new(query) loads |> List.wrap() |> Enum.flat_map(fn {key, value} -> case Ash.Resource.Info.relationship(query.resource, key) do nil -> [ NoSuchRelationship.exception( resource: query.resource, relationship: key, load_path: Enum.reverse(path) ) ] relationship -> cond do !Ash.Resource.Info.primary_action(relationship.destination, :read) -> [ NoReadAction.exception( resource: relationship.destination, when: "loading relationship #{relationship.name}" ) ] relationship.type == :many_to_many && !Ash.Resource.Info.primary_action(relationship.through, :read) -> [ NoReadAction.exception( resource: relationship.through, when: "loading relationship #{relationship.name}" ) ] true -> validate_matching_query_and_continue( value, query.resource, key, path, relationship ) end end end) end @doc false def do_filter(query, filter, opts \\ []) def do_filter(query, %Ash.Filter{} = filter, opts) do query = new(query) if Ash.DataLayer.data_layer_can?(query.resource, :filter) do context = %{} |> with_parent_stack(opts) |> with_conflicting_upsert_values(opts) new_filter = case query.filter do nil -> Ash.Filter.parse( query.resource, filter, context ) existing_filter -> Ash.Filter.add_to_filter( existing_filter, filter, :and, query.aggregates, query.calculations, context ) end case new_filter do {:ok, filter} -> case Ash.Filter.hydrate_refs( filter, %{ resource: query.resource, public?: false } |> with_parent_stack(opts) |> with_conflicting_upsert_values(opts) ) do {:ok, result} -> %{query | filter: result} {:error, error} -> add_error(query, :filter, error) end {:error, error} -> add_error(query, :filter, error) end else add_error(query, :filter, "Data layer does not support filtering") end end def do_filter(query, nil, _opts), do: new(query) def do_filter(query, [], _opts), do: new(query) def do_filter(query, statement, opts) do query = new(query) if Ash.DataLayer.data_layer_can?(query.resource, :filter) do context = %{} |> with_parent_stack(opts) |> with_conflicting_upsert_values(opts) filter = if query.filter do Ash.Filter.add_to_filter( query.filter, statement, :and, query.aggregates, query.calculations, context ) else Ash.Filter.parse( query.resource, statement, context ) end case filter do {:ok, filter} -> case Ash.Filter.hydrate_refs( filter, %{ resource: query.resource, public?: false } |> with_parent_stack(opts) |> with_conflicting_upsert_values(opts) ) do {:ok, result} -> %{query | filter: result} {:error, error} -> add_error(query, :filter, error) end {:error, error} -> add_error(query, :filter, error) end else add_error(query, :filter, "Data layer does not support filtering") end end defp with_parent_stack(context, opts) do if opts[:parent_stack] do parent_stack = List.wrap(opts[:parent_stack]) Map.update(context, :parent_stack, parent_stack, &(parent_stack ++ &1)) else context end end defp with_conflicting_upsert_values(context, opts) do case Keyword.fetch(opts, :conflicting_upsert_values) do {:ok, values} -> Map.put(context, :conflicting_upsert_values, values) :error -> context end end @doc """ Lock the query results. This must be run while in a transaction, and is not supported by all data layers. """ @spec lock(t() | Ash.Resource.t(), Ash.DataLayer.lock_type()) :: t() def lock(query, nil), do: %{query | lock: nil} def lock(query, lock_type) do query = new(query) if Ash.DataLayer.data_layer_can?(query.resource, {:lock, lock_type}) do %{query | lock: lock_type} else add_error( query, Ash.Error.Query.LockNotSupported.exception(resource: query.resource, lock_type: lock_type) ) end end @doc """ Sort the results based on attributes, aggregates or calculations. ## Format Your sort can be an atom, list of atoms, a keyword list, or a string. When an order is not specified, `:asc` is the default. See Sort Orders below for more on the available orders. ```elixir # sort by name ascending Ash.Query.sort(query, :name) # sort by name descending Ash.Query.sort(query, name: :desc) # sort by name descending with nils at the end Ash.Query.sort(query, name: :desc_nils_last) # sort by name descending, and title ascending Ash.Query.sort(query, name: :desc, title: :asc) # sort by name ascending Ash.Query.sort(query, "name") # sort by name descending, and title ascending Ash.Query.sort(query, "-name,title") # sort by name descending with nils at the end Ash.Query.sort(query, "--name") ``` ## Related Fields You can refer to related fields using the shorthand of `"rel1.rel2.field"`. For example: ```elixir # sort by the username of the comment's author. Ash.Query.sort(query, "comment.author.username") # Use as an atom for keyword lists Ash.Query.sort(query, "comment.author.username": :desc) ``` ## Expression Sorts You can use the `Ash.Expr.calc/2` macro to sort on expressions: ```elixir import Ash.Expr # Sort on an expression Ash.Query.sort(query, calc(count(friends), :desc)) # Specify a type (required in some cases when we can't determine a type) Ash.Query.sort(query, [{calc(fragment("some_sql(?)", field), type: :string), :desc}]) ``` ## Sort Strings A comma separated list of fields to sort on, each with an optional prefix. The prefixes are: * "+" - Same as no prefix. Sorts `:asc`. * "++" - Sorts `:asc_nils_first` * "-" - Sorts `:desc` * "--" - Sorts `:desc_nils_last` For example "foo,-bar,++baz,--buz" ## A list of sort strings Same prefix rules as above, but provided as a list. For example: ["foo", "-bar", "++baz", "--buz"] ## Calculations Calculation inputs can be provided by providing a map. To provide both inputs and an order, use a tuple with the first element being the inputs, and the second element being the order. ```elixir Ash.Query.sort(query, full_name: %{separator: " "}) Ash.Query.sort(query, full_name: {%{separator: " "}, :asc}) ``` ## Sort Orders The available orders are: - `:asc` - Sort values ascending, with lowest first and highest last, and `nil` values at the end - `:desc` - Sort values descending, with highest first and lowest last, and `nil` values at the beginning - `:asc_nils_first` - Sort values ascending, with lowest first and highest last, and `nil` values at the beginning - `:desc_nils_last` - Sort values descending, with highest first and lowest last, and `nil` values at the end ## Examples ```elixir Ash.Query.sort(query, [:foo, :bar]) Ash.Query.sort(query, [:foo, bar: :desc]) Ash.Query.sort(query, [foo: :desc, bar: :asc]) ``` See the guide on calculations for more. ## Options - `prepend?` - set to `true` to put your sort at the front of the list of a sort is already specified """ @spec sort(t() | Ash.Resource.t(), Ash.Sort.t(), opts :: Keyword.t()) :: t() def sort(query, sorts, opts \\ []) do query = new(query) if sorts == [] || sorts == nil do query else case Ash.Actions.Sort.process(query.resource, sorts) do {:ok, sorts} -> if Ash.DataLayer.data_layer_can?(query.resource, :sort) do if opts[:prepend?] && query.sort != [] do validated = query |> Map.put(:sort, []) |> sort(sorts) |> Map.get(:sort) new_sort_input_indices = Enum.map(query.sort_input_indices, &(&1 + 1)) %{query | sort: validated ++ query.sort, sort_input_indices: new_sort_input_indices} else sorts |> List.wrap() |> Enum.reduce(query, fn {sort, direction}, query -> %{query | sort: query.sort ++ [{sort, direction}]} sort, query -> %{query | sort: query.sort ++ [{sort, :asc}]} end) end else add_error(query, :sort, "Data layer does not support sorting") end {:error, error} -> Ash.Query.add_error(query, :sort, error) end end |> sequence_sorts() end @doc """ Get results distinct on the provided fields. Takes a list of fields to distinct on. Each call is additive, so to remove the `distinct` use `unset/2`. Examples: ``` Ash.Query.distinct(query, [:first_name, :last_name]) Ash.Query.distinct(query, :email) ``` """ @spec distinct(t() | Ash.Resource.t(), Ash.Sort.t()) :: t() def distinct(query, distincts) do query = new(query) distincts = List.wrap(distincts) if Ash.DataLayer.data_layer_can?(query.resource, :distinct) do case Sort.process(query.resource, distincts, query.aggregates, query.context) do {:ok, distincts} -> %{query | distinct: List.wrap(query.distinct) ++ List.wrap(distincts)} {:error, error} -> add_error(query, :distinct, error) end else add_error(query, :distinct, "Data layer does not support distincting") end end @doc """ Set a sort to determine how distinct records are selected. If none is set, any sort applied to the query will be used. This is useful if you want to control how the `distinct` records are selected without affecting (necessarily, it may affect it if there is no sort applied) the overall sort of the query """ @spec distinct_sort(t() | Ash.Resource.t(), Ash.Sort.t()) :: t() def distinct_sort(query, sorts, opts \\ []) do query = new(query) if sorts == [] || sorts == nil do query else if Ash.DataLayer.data_layer_can?(query.resource, :distinct_sort) do if opts[:prepend?] && query.distinct_sort != [] do query_sort = query.distinct_sort query |> Map.put(:distinct_sort, []) |> distinct_sort(sorts) |> distinct_sort(query_sort) else sorts |> List.wrap() |> Enum.reduce(query, fn {sort, direction}, query -> %{query | distinct_sort: query.distinct_sort ++ [{sort, direction}]} sort, query -> %{query | distinct_sort: query.distinct_sort ++ [{sort, :asc}]} end) end else add_error(query, :distinct_sort, "Data layer does not support distinct sorting") end end end @doc """ Applies a query to a list of records in memory. This function takes a query and applies its filters, sorting, pagination, and loading operations to an existing list of records in memory rather than querying the data layer. Useful for post-processing records or applying query logic to data from multiple sources. ## Examples # Apply filtering to records in memory iex> records = [%MyApp.Post{title: "A", published: true}, %MyApp.Post{title: "B", published: false}] iex> query = MyApp.Post |> Ash.Query.filter(published: true) iex> Ash.Query.apply_to(query, records) {:ok, [%MyApp.Post{title: "A", published: true}]} # Apply sorting and limiting iex> records = [%MyApp.Post{title: "C", likes: 5}, %MyApp.Post{title: "A", likes: 10}] iex> query = MyApp.Post |> Ash.Query.sort(likes: :desc) |> Ash.Query.limit(1) iex> Ash.Query.apply_to(query, records) {:ok, [%MyApp.Post{title: "A", likes: 10}]} # Apply with loading relationships iex> records = [%MyApp.Post{id: 1}, %MyApp.Post{id: 2}] iex> query = MyApp.Post |> Ash.Query.load(:author) iex> Ash.Query.apply_to(query, records, domain: MyApp.Blog) {:ok, [%MyApp.Post{id: 1, author: %MyApp.User{...}}, ...]} ## Options * `domain` - The domain to use for loading relationships * `actor` - The actor for authorization during loading * `tenant` - The tenant for multitenant operations * `parent` - Parent context for nested operations ## See also - `Ash.read/2` for querying the data layer directly - `load/3` for configuring relationship loading - `filter/2` for adding filter conditions """ @spec apply_to(t(), records :: list(Ash.Resource.record()), opts :: Keyword.t()) :: {:ok, list(Ash.Resource.record())} def apply_to(query, records, opts \\ []) do domain = query.domain || Ash.Resource.Info.domain(query.resource) || opts[:domain] || Ash.Actions.Helpers.maybe_embedded_domain(query.resource) || raise ArgumentError, "Could not determine domain for #{inspect(query)}, please provide the `:domain` option." with {:ok, records} <- Ash.Filter.Runtime.filter_matches(domain, records, query.filter, parent: opts[:parent], actor: opts[:actor] || query.context[:private][:actor], tenant: opts[:tenant] || query.tenant ), records <- Sort.runtime_sort(records, query.distinct_sort || query.sort, domain: domain), records <- Sort.runtime_distinct(records, query.distinct, domain: domain), records <- Sort.runtime_sort(records, query.sort, domain: domain), records <- Enum.drop(records, query.offset), records <- do_limit(records, query.limit), {:ok, records} <- Ash.load(records, query, domain: domain, reuse_values?: true) do {:ok, records} else {:error, error} -> {:error, Ash.Error.to_ash_error(error)} end end defp do_limit(records, nil), do: records defp do_limit(records, limit), do: Enum.take(records, limit) @doc """ Removes specified keys from the query, resetting them to their default values. This function allows you to "unset" or reset parts of a query back to their initial state. Useful when you want to remove filters, sorts, loads, or other query modifications while keeping the rest of the query intact. ## Examples # Remove multiple query aspects at once iex> query = MyApp.Post ...> |> Ash.Query.filter(published: true) ...> |> Ash.Query.sort(:created_at) ...> |> Ash.Query.limit(10) iex> Ash.Query.unset(query, [:filter, :sort, :limit]) %Ash.Query{filter: nil, sort: [], limit: nil, ...} # Remove just the sort from a query iex> query = MyApp.Post |> Ash.Query.sort([:title, :created_at]) iex> Ash.Query.unset(query, :sort) %Ash.Query{sort: [], ...} # Remove load statements iex> query = MyApp.Post |> Ash.Query.load([:author, :comments]) iex> Ash.Query.unset(query, :load) %Ash.Query{load: [], ...} # Reset pagination settings iex> query = MyApp.Post |> Ash.Query.limit(20) |> Ash.Query.offset(10) iex> Ash.Query.unset(query, [:limit, :offset]) %Ash.Query{limit: nil, offset: 0, ...} ## See also - `new/2` for creating fresh queries - `select/3`, `filter/2`, `sort/3` for building queries """ @spec unset(Ash.Resource.t() | t(), atom | [atom]) :: t() def unset(query, keys) when is_list(keys) do query = new(query) new = new(query.resource) keys |> Enum.reduce(query, fn key, query -> do_unset(query, key, new) end) end def unset(query, key) do new = new(query.resource) do_unset(query, key, new) query |> new() |> struct([{key, Map.get(new, key)}]) end defp do_unset(query, key, _new) when key in [:domain, :resource] do query end defp do_unset(query, :load, new) do query = unset(query, [:calculations, :aggregates, :load_through]) struct(query, [{:load, Map.get(new, :load)}]) end defp do_unset(query, :sort, _new) do %{query | sort: [], sort_input_indices: []} end defp do_unset(query, key, new) do struct(query, [{key, Map.get(new, key)}]) end @doc "Return the underlying data layer query for an ash query" def data_layer_query(ash_query, opts \\ []) def data_layer_query(%{errors: errors}, _opts) when errors not in [[], nil] do {:error, Ash.Error.to_error_class(errors)} end def data_layer_query(%{resource: resource, domain: domain} = ash_query, opts) do context = ash_query.context |> Map.put(:action, ash_query.action) |> Map.put_new(:private, %{}) |> put_in([:private, :tenant], ash_query.tenant) |> Map.put_new(:data_layer, %{}) context = if opts[:previous_combination] do Map.update!( context, :data_layer, &Map.put( &1, :previous_combination, opts[:previous_combination] && Ash.DataLayer.combination_acc(opts[:previous_combination], resource) ) ) else context end with {:ok, query, new_context} <- initial_data_layer_query(ash_query, domain, opts), {:ok, query} <- Ash.DataLayer.set_context( resource, query, Map.update!( context, :data_layer, &Map.merge(&1 || %{}, new_context) ) ), {:ok, query} <- add_tenant(query, ash_query), {:ok, query} <- Ash.DataLayer.select(query, ash_query.select, ash_query.resource), {:ok, query} <- Ash.DataLayer.sort(query, ash_query.sort, resource), {:ok, query} <- Ash.DataLayer.distinct_sort(query, ash_query.distinct_sort, resource), {:ok, query} <- Ash.DataLayer.add_aggregates( query, Map.values(ash_query.aggregates), ash_query.resource ), {:ok, query} <- maybe_filter(query, ash_query, opts), {:ok, query} <- Ash.DataLayer.add_calculations( query, opts[:data_layer_calculations] || [], ash_query.resource ), {:ok, query} <- Ash.DataLayer.distinct(query, ash_query.distinct, resource), {:ok, query} <- Ash.DataLayer.limit(query, ash_query.limit, resource), {:ok, query} <- Ash.DataLayer.offset(query, ash_query.offset, resource), {:ok, query} <- Ash.DataLayer.lock(query, ash_query.lock, resource), {:ok, query} <- maybe_return_query(query, resource, opts) do if opts[:no_modify?] || !ash_query.action || !ash_query.action.modify_query do {:ok, query} else case ash_query.action.modify_query do {m, f, a} -> apply(m, f, a ++ [ash_query, query]) modify_query when is_function(modify_query, 2) -> modify_query.(ash_query, query) end end else {:error, error} -> {:error, error} end end defp initial_data_layer_query(ash_query, domain, opts) do cond do opts[:initial_query] -> {:ok, opts[:initial_query], %{}} ash_query.combination_of != [] -> combination = hd(ash_query.combination_of) default_select = MapSet.to_list( Ash.Resource.Info.selected_by_default_attribute_names(ash_query.resource) ) case combination_queries(ash_query) do {:ok, combinations, previous} -> with {:ok, query} <- Ash.DataLayer.combination_of(combinations, ash_query.resource, domain) do {:ok, query, %{ previous_combination: previous && Ash.DataLayer.combination_acc(previous, ash_query.resource), combination_of_queries?: true, combination_fieldset: Enum.uniq( (combination.select || default_select) ++ Map.keys(combination.calculations) ) }} end {:error, error} -> {:error, error} end true -> {:ok, opts[:initial_query] || Ash.DataLayer.resource_to_query(ash_query.resource, domain), %{}} end end defp combination_queries(query) do base_query = Ash.Query.new(query.resource) Enum.reduce_while( query.combination_of, {:ok, [], nil}, fn combination, {:ok, combinations, previous} -> calculations = Enum.map(combination.calculations, fn {name, calc} -> {%{calc | name: name, load: nil}, Ash.Resource.Calculation.expression(calc.module, calc.opts, calc.context)} end) base_query |> Ash.Query.set_tenant(query.tenant) |> limit(combination.limit) |> offset(combination.offset) |> do_filter(combination.filter) |> sort(combination.sort) |> select( combination.select || MapSet.to_list(Ash.Resource.Info.selected_by_default_attribute_names(query.resource)) ) |> Ash.Query.set_context(query.context) |> Ash.Query.set_context(%{data_layer: %{combination_query?: true}}) |> then(fn %{valid?: true} = combination_query -> case data_layer_query(combination_query, previous_combination: previous, data_layer_calculations: calculations ) do {:ok, combination_query} -> {:cont, {:ok, [{combination.type, combination_query} | combinations], combination_query}} {:error, error} -> {:halt, {:error, error}} end %{valid?: false, errors: errors} -> {:halt, {:error, errors}} end) end ) |> then(fn {:ok, unions, previous} -> {:ok, Enum.reverse(unions), previous} {:error, error} -> {:error, error} end) end defp maybe_return_query(query, resource, opts) do if Keyword.get(opts, :run_return_query?, true) do Ash.DataLayer.return_query(query, resource) else {:ok, query} end end defp add_tenant(query, ash_query) do with :context <- Ash.Resource.Info.multitenancy_strategy(ash_query.resource), tenant when not is_nil(tenant) <- ash_query.to_tenant, {:ok, query} <- Ash.DataLayer.set_tenant(ash_query.resource, query, ash_query.to_tenant) do {:ok, query} else {:error, error} -> {:error, error} _ -> {:ok, query} end end @doc """ Add an error to the errors list and mark the query as invalid. See `Ash.Error.to_ash_error/3` for more on supported values for `error` ## Inconsistencies The `path` argument is the second argument here, but the third argument in `Ash.ActionInput.add_error/2` and `Ash.Changeset.add_error/2`. This will be fixed in 4.0. """ @spec add_error(t(), path :: Ash.Error.path_input(), Ash.Error.error_input()) :: t() @spec add_error(t(), Ash.Error.error_input()) :: t() def add_error(query, path \\ [], error) def add_error(query, _path, []) do query end def add_error(query, path, errors) when is_list(errors) do if Keyword.keyword?(errors) do error = errors |> to_query_error() |> Ash.Error.set_path(path) add_error(query, error) else Enum.reduce(errors, query, &add_error(&2, path, &1)) end end def add_error(query, path, error) do path = List.wrap(path) query = new(query) error = error |> Ash.Error.to_ash_error() |> Ash.Error.set_path(path) %{query | errors: [error | query.errors], valid?: false} end defp to_query_error(keyword) do error = if keyword[:field] do InvalidArgument.exception( field: keyword[:field], message: keyword[:message], value: keyword[:value], vars: keyword ) else InvalidQuery.exception( fields: keyword[:fields] || [], message: keyword[:message], value: keyword[:value], vars: keyword ) end if keyword[:path] do Ash.Error.set_path(error, keyword[:path]) else error end end defp validate_matching_query_and_continue(value, resource, key, path, relationship) do %{destination: relationship_resource} = relationship case value do %__MODULE__{resource: query_resource} = destination_query when query_resource != relationship_resource -> [ Ash.Error.Load.InvalidQuery.exception( resource: resource, relationship: key, query: destination_query, load_path: Enum.reverse(path) ) ] %__MODULE__{} = destination_query -> if Map.get(relationship, :manual) && (destination_query.limit || (destination_query.offset && destination_query.offset != 0)) do [ Ash.Error.Load.InvalidQuery.exception( resource: resource, relationship: key, query: destination_query, load_path: Enum.reverse(path) ) ] else do_validate_load(relationship.destination, destination_query, [key | path]) end other -> do_validate_load(relationship.destination, other, [key | path]) end end defp maybe_filter(query, %{filter: nil}, _) do {:ok, query} end defp maybe_filter(query, ash_query, opts) do case Ash.DataLayer.filter(query, ash_query.filter, ash_query.resource) do {:ok, filtered} -> if Keyword.get(opts, :only_validate_filter?, false) do {:ok, query} else {:ok, filtered} end {:error, error} -> {:error, error} end end defp set_load_domain(nil, _), do: nil defp set_load_domain([], _), do: [] defp set_load_domain(%__MODULE__{} = query, domain) do set_domain(query, domain) end defp set_load_domain(loads, domain) do Enum.map(loads, fn {key, further} -> {key, set_load_domain(further, domain)} end) end defp merge_load( %__MODULE__{ load: left_loads, timeout: left_timeout, calculations: left_calculations, aggregates: left_aggregates, tenant: left_tenant, select: left_select }, %__MODULE__{ load: right_loads, timeout: right_timeout, aggregates: right_aggregates, calculations: right_calculations, select: right_select } = query, opts ) do select = cond do is_nil(left_select) and is_nil(right_select) -> Enum.to_list(Ash.Resource.Info.selected_by_default_attribute_names(query.resource)) is_nil(left_select) -> right_select is_nil(right_select) -> left_select true -> Enum.uniq(left_select ++ right_select) end %{ query | load: left_loads, calculations: Map.merge(left_calculations, right_calculations), aggregates: Map.merge(left_aggregates, right_aggregates), timeout: left_timeout || right_timeout, select: select } |> merge_load(right_loads, opts) |> set_tenant(query.tenant || left_tenant) end defp merge_load(%__MODULE__{} = query, right, opts) do load(query, right, opts) end end