How to parse JSON format fields in pgsql?

In PostgreSQL, you can use the functions json_to_record or json_to_recordset to parse fields in JSON format.

Assuming you have a JSON field named “data” that contains the following content:

{
  "name": "John",
  "age": 30,
  "address": {
    "city": "New York",
    "state": "NY"
  }
}

You can use the following query to parse this field:

SELECT json_to_record(data) AS (name text, age int, address json)
FROM your_table;

The above query will return a result set containing parsed fields.

If your JSON field is an array and you want to parse it into multiple rows, you can use the json_to_recordset function. For example, if you have a field named data containing the following content:

[
  {
    "name": "John",
    "age": 30
  },
  {
    "name": "Jane",
    "age": 25
  }
]

You can use the following query to parse this field:

SELECT *
FROM json_to_recordset(data) AS (name text, age int);

The above query will return two rows, each containing a field from a parsed JSON object.

Please be aware that you need to enable support for the json or jsonb data types in PostgreSQL, as well as for related JSON functions and operators. You can ensure they are available by running the following command:

CREATE EXTENSION IF NOT EXISTS "json";
CREATE EXTENSION IF NOT EXISTS "jsonb";

These commands will create the necessary extensions in your database.