Blink.Adapter behaviour (blink v0.8.0)

Defines the adapter behaviour and dispatches to the selected adapter.

Adapters are responsible for implementing database-specific bulk insert operations. Each adapter must implement the call/4 callback to bulk insert rows into a table using a database-specific mechanism (e.g., PostgreSQL's COPY command).

Example

defmodule MyApp.CustomAdapter do
  @behaviour Blink.Adapter

  @impl true
  def call(items, table_name, repo, opts) do
    # Custom bulk copy implementation
    :ok
  end
end

# Usage
run(seeder, MyApp.Repo, adapter: MyApp.CustomAdapter)

# Or via copy_to_table/4
Blink.copy_to_table(items, "users", MyApp.Repo, adapter: MyApp.CustomAdapter)

Summary

Callbacks

call(rows, table_name, repo, opts)

Performs a bulk copy operation to insert rows into a database table.

Functions

copy_to_table(rows, table_name, repo, opts \\ [])

Callbacks

call(rows, table_name, repo, opts)

@callback call(
  rows :: Enumerable.t(),
  table_name :: String.t(),
  repo :: Ecto.Repo.t(),
  opts :: Keyword.t()
) :: :ok

Performs a bulk copy operation to insert rows into a database table.

Parameters

rows - An enumerable (list or stream) of maps where each map represents a row to insert. All maps must have the same keys, which correspond to the table columns.
table_name - The name of the table to insert into (string).
repo - An Ecto repository module.
opts - Keyword list of adapter-specific options. Adapters own their option vocabulary and should validate it, raising ArgumentError on unknown keys or invalid values (Keyword.validate!/2 covers the former).

Blink.Seeder.run/3 forwards its options here, including :atomic. With atomic: true it opens a transaction on the calling process's connection and relies on the adapter to perform the whole copy in the calling process, so that the copy enrolls in the transaction. An adapter that hands batches to other processes — each checking out its own connection — silently voids that all-or-nothing guarantee. Support :atomic only by copying in the calling process; otherwise reject the option, so a failed seed cannot pass for rolled back when parts of it committed.

Returns

:ok - When the copy operation succeeds

Raises an exception when the copy operation fails.

Functions

copy_to_table(rows, table_name, repo, opts \\ [])

@spec copy_to_table(
  rows :: Enumerable.t(),
  table_name :: String.t(),
  repo :: Ecto.Repo.t(),
  opts :: Keyword.t()
) :: :ok