Selecto v0.3.8

Selecto.Output.Transformers.Json (Selecto v0.3.8)

JSON transformer for Selecto query results.

Provides JSON serialization with configurable options for null handling, metadata inclusion, pretty printing, and streaming support for large datasets.

options

 Options

  • :include_meta - Include query metadata in response (default: false)
  • :pretty - Pretty print JSON output (default: false)
  • :null_handling - How to handle nil values: :null, :omit, :empty_string (default: :null)
  • :keys - Key format: :strings, :atoms (default: :strings)
  • :coerce_types - Enable type coercion (default: false)
  • :date_format - Date serialization format: :iso8601, :unix, :string (default: :iso8601)
  • :decimal_format - Decimal format: :string, :float (default: :string)

examples

 Examples 

# Basic JSON serialization
{:ok, json} = Json.transform(rows, columns, %{}, [])

# JSON with metadata
{:ok, json} = Json.transform(rows, columns, %{}, [include_meta: true])

# Pretty printed JSON with null omission
{:ok, json} = Json.transform(rows, columns, %{}, [
  pretty: true,
  null_handling: :omit
])

# Streaming for large datasets
stream = Json.stream_transform(rows, columns, %{}, [pretty: true])

Link to this section Summary

Types

json_option()
json_options()

Functions

stream_transform(rows, columns, aliases, options \\ [])

Transform query results to a JSON stream for large datasets.

transform(rows, columns, aliases, options \\ [])

Transform query results to JSON string.

Link to this section Types

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json_option()

@type json_option() ::
  {:include_meta, boolean()}
  | {:pretty, boolean()}
  | {:null_handling, :null | :omit | :empty_string}
  | {:keys, :strings | :atoms}
  | {:coerce_types, boolean()}
  | {:date_format, :iso8601 | :unix | :string}
  | {:decimal_format, :string | :float}
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json_options()

@type json_options() :: [json_option()]

Link to this section Functions

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stream_transform(rows, columns, aliases, options \\ [])

@spec stream_transform([list()] | Enumerable.t(), [String.t()], map(), json_options()) ::
  Enumerable.t()

Transform query results to a JSON stream for large datasets.

Returns a stream that yields JSON strings, useful for processing large result sets without loading everything into memory.

Link to this function

transform(rows, columns, aliases, options \\ [])

@spec transform([list()], [String.t()], map(), json_options()) ::
  {:ok, String.t()} | {:error, Selecto.Error.t()}

Transform query results to JSON string.

Returns a JSON string representation of the query results with configurable serialization options.