PostgreSQL row_to_json() Function

The PostgreSQL row_to_json() function converts a value of an SQL composite type to a JSON object and returns it.

row_to_json() Syntax

The syntax of the PostgreSQL row_to_json() function comes in two forms:

row_to_json(any_row RECORD) -> JSON

or

row_to_json(any_row RECORD, pretty BOOLEAN) -> JSON

Parameters

any_array

Required. The value of the SQL composite type to convert to a JSON object. We can use the row expression to construct a value of a composite type.

pretty

Required. Whether to add newlines between top-level elements to prettify the output JSON value.

Return value

The PostgreSQL row_to_json() function returns a JSON object converted from a value of a specified SQL composite type.

If the parameter pretty is true, the row_to_json() function will prettify the JSON by adding newlines between top-level elements of the output JSON object.

row_to_json() Examples

This example shows how to use the PostgreSQL row_to_json() function to convert a SQL composite type value to a JSON object.

SELECT row_to_json(row('Tom', 20, 'He likes sports.'));

                 row_to_json
----------------------------------------------
 {"f1":"Tom","f2":20,"f3":"He likes sports."}

Here, we use the row expression row('Tom', 20, 'He likes sports.') to construct a value of a composite type. The value of this composite type contains 3 elements: 'Tom', 20 and 'He likes sports.'.

When converting a composite type value into a JSON object, the row_to_json() function automatically generates keys of the object in the format fn, where n is a number, increasing from 1.

You can provide true for the parameter pretty to beautify the output JSON object like:

SELECT row_to_json(row('Tom', 20, 'He likes sports.'), true);

        row_to_json
---------------------------
 {"f1":"Tom",             +
  "f2":20,                +
  "f3":"He likes sports."}