1943a5da5f
1. move `group_concat` from string-functions to aggregate-functions. 2. add `json_array`/`json_object`/`json_quote` to sidebar file. 3. move `json_array`/`json_object`/`json_quote`/`get_json_double`/`get_json_int`/`get_json_string` to json-functions. 4. change `group_concat` document to uppercase
3.4 KiB
3.4 KiB
title, language
| title | language |
|---|---|
| get_json_string | en |
get_json_string
description
Syntax
VARCHAR get_json_string (VARCHAR json str, VARCHAR json path)
Parse and retrieve the string content of the specified path in the JSON string. Where json_path must start with the $symbol and use. as the path splitter. If the path contains..., double quotation marks can be used to surround it. Use [] to denote array subscripts, starting at 0. The content of path cannot contain ",[and]. If the json_string format is incorrect, or the json_path format is incorrect, or matches cannot be found, NULL is returned.
example
- Get the value of key as "k1"
mysql> SELECT get_json_string('{"k1":"v1", "k2":"v2"}', "$.k1");
+---------------------------------------------------+
| get_json_string('{"k1":"v1", "k2":"v2"}', '$.k1') |
+---------------------------------------------------+
| v1 |
+---------------------------------------------------+
- Get the second element of the array whose key is "my. key"
mysql> SELECT get_json_string('{"k1":"v1", "my.key":["e1", "e2", "e3"]}', '$."my.key"[1]');
+------------------------------------------------------------------------------+
| get_json_string('{"k1":"v1", "my.key":["e1", "e2", "e3"]}', '$."my.key"[1]') |
+------------------------------------------------------------------------------+
| e2 |
+------------------------------------------------------------------------------+
- Get the first element in an array whose secondary path is k1. key - > K2
mysql> SELECT get_json_string('{"k1.key":{"k2":["v1", "v2"]}}', '$."k1.key".k2[0]');
+-----------------------------------------------------------------------+
| get_json_string('{"k1.key":{"k2":["v1", "v2"]}}', '$."k1.key".k2[0]') |
+-----------------------------------------------------------------------+
| v1 |
+-----------------------------------------------------------------------+
- Get all the values in the array where the key is "k1"
mysql> SELECT get_json_string('[{"k1":"v1"}, {"k2":"v2"}, {"k1":"v3"}, {"k1":"v4"}]', '$.k1');
+---------------------------------------------------------------------------------+
| get_json_string('[{"k1":"v1"}, {"k2":"v2"}, {"k1":"v3"}, {"k1":"v4"}]', '$.k1') |
+---------------------------------------------------------------------------------+
| ["v1","v3","v4"] |
+---------------------------------------------------------------------------------+
keyword
GET_JSON_STRING,GET,JSON,STRING