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26 lines
621 B
Elixir
26 lines
621 B
Elixir
defmodule AshPostgres.CustomAggregate do
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@moduledoc """
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A custom aggregate implementation for ecto.
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"""
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@doc """
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The dynamic expression to create the aggregate.
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The binding refers to the resource being aggregated,
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use `as(^binding)` to reference it.
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For example:
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Ecto.Query.dynamic(
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[],
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fragment("string_agg(?, ?)", field(as(^binding), ^opts[:field]), ^opts[:delimiter])
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)
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"""
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@callback dynamic(opts :: Keyword.t(), binding :: integer) :: Ecto.Query.dynamic_expr()
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defmacro __using__(_) do
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quote do
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@behaviour AshPostgres.CustomAggregate
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end
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end
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end
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