jsonb_populate_record() and json_populate_record()

Purpose: Convert a JSON object into the equivalent SQL record.

Signature For the jsonb variant:

input value:       anyelement, jsonb
return value:      anyelement

Notes: Each function in this pair requires that the supplied JSON value is an object. The data type of the record must be defined as a schema-level type whose name is passed via the function's first formal parameter using the locution NULL:type_identifier. The JSON value is passed using the second formal parameter.

Use this ysqlsh script to create the required types "t1" and "t2", and then to execute the ASSERT.

create type t1 as ( d int, e text);
create type t2 as (a int, b text[], c t1);

do $body$
  nested_object constant jsonb :=
    '{"a": 42, "b": ["cat", "dog"], "c": {"d": 17, "e": "frog"}}';

  result constant t2 := jsonb_populate_record(null::t2, nested_object);

  expected_a constant int := 42;
  expected_b constant text[] := array['cat', 'dog'];
  expected_c constant t1 := (17, 'frog');
  expected_result constant t2 := (expected_a, expected_b, expected_c);
    result = expected_result,