get_json_double
Description
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.
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
-
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 |
+-------------------------------------------------+ -
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 |
+---------------------------------------------------------------------------+ -
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