get_json_double

This function analyzes and gets the floating point value from a specified path in json string. json_path must start with $ and use . as the path separator.

tip

All of the JSON functions and operators are listed in the navigation and on the overview page

Accelerate your queries with generated columns

If the path includes ., it could be circled by " and ".

[ ] is used as the array subscripts which start from 0.

Content in the path should not contain " , [ and ].

If the format of json_string or json_path is wrong, this function will return NULL.

Syntax

DOUBLE get_json_double(VARCHAR json_str, VARCHAR json_path)

Examples

1. Get the value whose key is "k1"

   MySQL > SELECT get_json_double('{"k1":1.3, "k2":"2"}', "$.k1");
   +-------------------------------------------------+
   | get_json_double('{"k1":1.3, "k2":"2"}', '$.k1') |
   +-------------------------------------------------+
   |                                             1.3 |
   +-------------------------------------------------+

2. Get the second element in the array whose key is "my.key"

   MySQL > SELECT get_json_double('{"k1":"v1", "my.key":[1.1, 2.2, 3.3]}', '$."my.key"[1]');
   +---------------------------------------------------------------------------+
   | get_json_double('{"k1":"v1", "my.key":[1.1, 2.2, 3.3]}', '$."my.key"[1]') |
   +---------------------------------------------------------------------------+
   |                                                                       2.2 |
   +---------------------------------------------------------------------------+

3. Get the first element in the array whose path is k1.key -> k2.

   MySQL > SELECT get_json_double('{"k1.key":{"k2":[1.1, 2.2]}}', '$."k1.key".k2[0]');
   +---------------------------------------------------------------------+
   | get_json_double('{"k1.key":{"k2":[1.1, 2.2]}}', '$."k1.key".k2[0]') |
   +---------------------------------------------------------------------+
   |                                                                 1.1 |
   +---------------------------------------------------------------------+

keyword

GET_JSON_DOUBLE,GET,JSON,DOUBLE