InfluxElixir.Client.Local.InfluxQL (InfluxElixir v0.1.35)

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The InfluxQL SELECT subset InfluxElixir.Client.Local answers, shaped the way InfluxDB 3 answers it (verified against the engine; see docs/design/2026-09-23_local-influxql.md).

InfluxQL is not SQL with other keywords. Every row carries "iox::measurement" and "time"; rows come back in time order; a row with no selected field value is dropped; an unknown column or measurement is an empty result, not an error; aggregates are named after the function (mean, count, ...) and put time at the epoch, except a lone selector (MAX, MIN, FIRST, LAST), which returns its point's time and tags; LIMIT and OFFSET apply per GROUP BY series.

This module is pure. parse/1 turns the statement into a query map; run/3 shapes rows the caller has already filtered with the statement's WHERE clause (Client.Local runs it through its SQL engine).

Refused by name, rather than answered wrongly: GROUP BY time(...) (the engine fills every empty bucket), regular expressions, fill(), INTO, SLIMIT/SOFFSET, subqueries, GROUP BY *, functions other than MEAN SUM COUNT MIN MAX FIRST LAST, F(*) other than COUNT(*), and plain columns beside anything but a single selector.

Summary

Types

item()

A select item: every column, a column, or a function of a column.

query()

A parsed SELECT.

Functions

parse(statement)

Parses an InfluxQL SELECT. Returns {:error, message} for syntax the engine rejects and for the constructs listed in the moduledoc.

run(query, rows, tags)

Shapes rows — the measurement's points already filtered by the statement's WHERE, as SQL row maps with "time" — into the engine's answer. tags names the measurement's tag columns; everything else but time is a field.

Types

item()

@type item() ::
  :star
  | {:column, binary(), binary()}
  | {:aggregate, binary(), binary() | :star, binary() | nil}

A select item: every column, a column, or a function of a column.

query()

@type query() :: %{
  items: [item()],
  measurement: binary(),
  where: binary() | nil,
  group_by: [binary()],
  descending: boolean(),
  limit: non_neg_integer() | nil,
  offset: non_neg_integer()
}

A parsed SELECT.

Functions

parse(statement)

@spec parse(binary()) :: {:ok, query()} | {:error, binary()}

Parses an InfluxQL SELECT. Returns {:error, message} for syntax the engine rejects and for the constructs listed in the moduledoc.

run(query, rows, tags)

@spec run(query(), [map()], MapSet.t(binary())) :: [map()]

Shapes rows — the measurement's points already filtered by the statement's WHERE, as SQL row maps with "time" — into the engine's answer. tags names the measurement's tag columns; everything else but time is a field.