1.JSON_CONTAINS(target, candidate[, path])
返回0或1,来判断目标(target)JSON document 是否包含给出的候选(candidate) JSON document 。如果存在path参数,则将会在path的范围内查找。如果有任何一个参数是null或者是path参数的表示的路径在target中找不到,则函数会返回null
mysql> SET @j = '{"a": 1, "b": 2, "c": {"d": 4}}'; mysql> SET @j2 = '1'; mysql> SELECT JSON_CONTAINS(@j, @j2, '$.a'); +-------------------------------+ | JSON_CONTAINS(@j, @j2, '$.a') | +-------------------------------+ | 1 | +-------------------------------+ mysql> SELECT JSON_CONTAINS(@j, @j2, '$.b'); +-------------------------------+ | JSON_CONTAINS(@j, @j2, '$.b') | +-------------------------------+ | 0 | +-------------------------------+ mysql> SET @j2 = '{"d": 4}'; mysql> SELECT JSON_CONTAINS(@j, @j2, '$.a'); +-------------------------------+ | JSON_CONTAINS(@j, @j2, '$.a') | +-------------------------------+ | 0 | +-------------------------------+ mysql> SELECT JSON_CONTAINS(@j, @j2, '$.c'); +-------------------------------+ | JSON_CONTAINS(@j, @j2, '$.c') | +-------------------------------+ | 1 | +-------------------------------+ mysql> SELECT JSON_CONTAINS(@j, @j2, '$.r'); +-------------------------------+ | JSON_CONTAINS(@j, @j2, '$.r') | +-------------------------------+ | NULL | +-------------------------------+ mysql> SELECT JSON_CONTAINS(@j, @j2, '$.c.d'); +---------------------------------+ | JSON_CONTAINS(@j, @j2, '$.c.d') | +---------------------------------+ | 0 | +---------------------------------+ #value是数组的情况 mysql> SET @j = '{"a": [1,2,3], "b": 2, "c": {"d": 4}}'; Query OK, 0 rows affected (0.00 sec) mysql> SELECT JSON_CONTAINS(@j, @j2, '$.a'); +-------------------------------+ | JSON_CONTAINS(@j, @j2, '$.a') | +-------------------------------+ | 1 | +-------------------------------+
2.JSON_CONTAINS_PATH(json_doc, one_or_all, path[, path] ...)
返回0或1,来判断给定的JSON document中是否存在给出的path(可以是多个)。简单的说,就是查找key是否存在的,上面的JSON_CONTAINS是查找value。
one_or_all参数有两个值:
'one': 如果有至少一个path存在则返回1,否则返回0。
'all': 如果所有path都存在则返回1,否则返回0。
mysql> SET @j = '{"a": 1, "b": 2, "c": {"d": 4}}'; mysql> SELECT JSON_CONTAINS_PATH(@j, 'one', '$.a', '$.e'); +---------------------------------------------+ | JSON_CONTAINS_PATH(@j, 'one', '$.a', '$.e') | +---------------------------------------------+ | 1 | +---------------------------------------------+ mysql> SELECT JSON_CONTAINS_PATH(@j, 'all', '$.a', '$.e'); +---------------------------------------------+ | JSON_CONTAINS_PATH(@j, 'all', '$.a', '$.e') | +---------------------------------------------+ | 0 | +---------------------------------------------+ mysql> SELECT JSON_CONTAINS_PATH(@j, 'one', '$.c.d'); +----------------------------------------+ | JSON_CONTAINS_PATH(@j, 'one', '$.c.d') | +----------------------------------------+ | 1 | +----------------------------------------+ mysql> SELECT JSON_CONTAINS_PATH(@j, 'one', '$.a.d'); +----------------------------------------+ | JSON_CONTAINS_PATH(@j, 'one', '$.a.d') | +----------------------------------------+ | 0 | +----------------------------------------+
3.JSON_EXTRACT(json_doc, path[, path] ...)
用作提取JSON中的某个value,如果有多个path参数,返回的结果将是一个JSON数组。
#官方例子 mysql> SELECT JSON_EXTRACT('[10, 20, [30, 40]]', '$[1]'); +--------------------------------------------+ | JSON_EXTRACT('[10, 20, [30, 40]]', '$[1]') | +--------------------------------------------+ | 20 | +--------------------------------------------+ mysql> SELECT JSON_EXTRACT('[10, 20, [30, 40]]', '$[1]', '$[0]'); +----------------------------------------------------+ | JSON_EXTRACT('[10, 20, [30, 40]]', '$[1]', '$[0]') | +----------------------------------------------------+ | [20, 10] | +----------------------------------------------------+ mysql> SELECT JSON_EXTRACT('[10, 20, [30, 40]]', '$[2][*]'); +-----------------------------------------------+ | JSON_EXTRACT('[10, 20, [30, 40]]', '$[2][*]') | +-----------------------------------------------+ | [30, 40] | +-----------------------------------------------+ #以下是幻幻自己的测试例子,继续使用上面的@j mysql> SELECT JSON_EXTRACT(@j, '$.a'); +-------------------------+ | JSON_EXTRACT(@j, '$.a') | +-------------------------+ | [1, 2, 3] | +-------------------------+ mysql> SELECT JSON_EXTRACT(@j, '$.c.d'); +---------------------------+ | JSON_EXTRACT(@j, '$.c.d') | +---------------------------+ | 4 | +---------------------------+ mysql> SELECT JSON_EXTRACT(@j, '$.c.d', '$.a'); +----------------------------------+ | JSON_EXTRACT(@j, '$.c.d', '$.a') | +----------------------------------+ | [4, [1, 2, 3]] | +----------------------------------+
4.column->path
在MySQL 5.7.9及以后的版本中,使用 ->操作符来简写 JSON_EXTRACT() 函数,只能在只有2个参数的时候使用,操作符左边是列名,右边是JSON路径。
mysql> SELECT c, JSON_EXTRACT(c, "$.id"), g > FROM jemp > WHERE JSON_EXTRACT(c, "$.id") > 1 > ORDER BY JSON_EXTRACT(c, "$.name"); +-------------------------------+-----------+------+ | c | c->"$.id" | g | +-------------------------------+-----------+------+ | {"id": "3", "name": "Barney"} | "3" | 3 | | {"id": "4", "name": "Betty"} | "4" | 4 | | {"id": "2", "name": "Wilma"} | "2" | 2 | +-------------------------------+-----------+------+ 3 rows in set (0.00 sec) mysql> SELECT c, c->"$.id", g > FROM jemp > WHERE c->"$.id" > 1 > ORDER BY c->"$.name"; +-------------------------------+-----------+------+ | c | c->"$.id" | g | +-------------------------------+-----------+------+ | {"id": "3", "name": "Barney"} | "3" | 3 | | {"id": "4", "name": "Betty"} | "4" | 4 | | {"id": "2", "name": "Wilma"} | "2" | 2 | +-------------------------------+-----------+------+ 3 rows in set (0.00 sec)
这个功能不只限于SELECT操作:
mysql> ALTER TABLE jemp ADD COLUMN n INT; Query OK, 0 rows affected (0.68 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> UPDATE jemp SET n=1 WHERE c->"$.id" = "4"; Query OK, 1 row affected (0.04 sec) Rows matched: 1 Changed: 1 Warnings: 0 mysql> SELECT c, c->"$.id", g, n > FROM jemp > WHERE JSON_EXTRACT(c, "$.id") > 1 > ORDER BY c->"$.name"; +-------------------------------+-----------+------+------+ | c | c->"$.id" | g | n | +-------------------------------+-----------+------+------+ | {"id": "3", "name": "Barney"} | "3" | 3 | NULL | | {"id": "4", "name": "Betty"} | "4" | 4 | 1 | | {"id": "2", "name": "Wilma"} | "2" | 2 | NULL | +-------------------------------+-----------+------+------+ 3 rows in set (0.00 sec) mysql> DELETE FROM jemp WHERE c->"$.id" = "4"; Query OK, 1 row affected (0.04 sec) mysql> SELECT c, c->"$.id", g, n > FROM jemp > WHERE JSON_EXTRACT(c, "$.id") > 1 > ORDER BY c->"$.name"; +-------------------------------+-----------+------+------+ | c | c->"$.id" | g | n | +-------------------------------+-----------+------+------+ | {"id": "3", "name": "Barney"} | "3" | 3 | NULL | | {"id": "2", "name": "Wilma"} | "2" | 2 | NULL | +-------------------------------+-----------+------+------+ 2 rows in set (0.00 sec)
也可以用于JSON数组:
mysql> CREATE TABLE tj10 (a JSON, b INT); Query OK, 0 rows affected (0.26 sec) mysql> INSERT INTO tj10 > VALUES ("[3,10,5,17,44]", 33), ("[3,10,5,17,[22,44,66]]", 0); Query OK, 1 row affected (0.04 sec) mysql> SELECT a->"$[4]" FROM tj10; +--------------+ | a->"$[4]" | +--------------+ | 44 | | [22, 44, 66] | +--------------+ 2 rows in set (0.00 sec) mysql> SELECT * FROM tj10 WHERE a->"$[0]" = 3; +------------------------------+------+ | a | b | +------------------------------+------+ | [3, 10, 5, 17, 44] | 33 | | [3, 10, 5, 17, [22, 44, 66]] | 0 | +------------------------------+------+ 2 rows in set (0.00 sec)
支持嵌套数组。如果没有找到对应的key,则返回null:
mysql> SELECT * FROM tj10 WHERE a->"$[4][1]" IS NOT NULL; +------------------------------+------+ | a | b | +------------------------------+------+ | [3, 10, 5, 17, [22, 44, 66]] | 0 | +------------------------------+------+ mysql> SELECT a->"$[4][1]" FROM tj10; +--------------+ | a->"$[4][1]" | +--------------+ | NULL | | 44 | +--------------+ 2 rows in set (0.00 sec)
5.column->>path
这个表达式相当于JSON_UNQUOTE(JSON_EXTRACT())两个函数的组合。可用于SELECT列表, WHERE 和 HAVING 条件, ORDER BY 和 GROUP BY 条件。
mysql> SELECT * FROM jemp WHERE g > 2; +-------------------------------+------+ | c | g | +-------------------------------+------+ | {"id": "3", "name": "Barney"} | 3 | | {"id": "4", "name": "Betty"} | 4 | +-------------------------------+------+ 2 rows in set (0.01 sec) mysql> SELECT c->'$.name' AS name -> FROM jemp WHERE g > 2; +----------+ | name | +----------+ | "Barney" | | "Betty" | +----------+ 2 rows in set (0.00 sec) mysql> SELECT JSON_UNQUOTE(c->'$.name') AS name -> FROM jemp WHERE g > 2; +--------+ | name | +--------+ | Barney | | Betty | +--------+ 2 rows in set (0.00 sec) mysql> SELECT c->>'$.name' AS name -> FROM jemp WHERE g > 2; +--------+ | name | +--------+ | Barney | | Betty | +--------+ 2 rows in set (0.00 sec)
它也可以用于JSON数组:
mysql> CREATE TABLE tj10 (a JSON, b INT); Query OK, 0 rows affected (0.26 sec) mysql> INSERT INTO tj10 VALUES -> ('[3,10,5,"x",44]', 33), -> ('[3,10,5,17,[22,"y",66]]', 0); Query OK, 2 rows affected (0.04 sec) Records: 2 Duplicates: 0 Warnings: 0 mysql> SELECT a->"$[3]", a->"$[4][1]" FROM tj10; +-----------+--------------+ | a->"$[3]" | a->"$[4][1]" | +-----------+--------------+ | "x" | NULL | | 17 | "y" | +-----------+--------------+ 2 rows in set (0.00 sec) mysql> SELECT a->>"$[3]", a->>"$[4][1]" FROM tj10; +------------+---------------+ | a->>"$[3]" | a->>"$[4][1]" | +------------+---------------+ | x | NULL | | 17 | y | +------------+---------------+ 2 rows in set (0.00 sec)
6.JSON_KEYS(json_doc[, path])
这个函数用来获取JSON中的key,以JSON数组形式返回。如果没有指定path参数,则默认找的是第一级的key。
mysql> SELECT JSON_KEYS('{"a": 1, "b": {"c": 30}}'); +---------------------------------------+ | JSON_KEYS('{"a": 1, "b": {"c": 30}}') | +---------------------------------------+ | ["a", "b"] | +---------------------------------------+ mysql> SELECT JSON_KEYS('{"a": 1, "b": {"c": 30}}', '$.b'); +----------------------------------------------+ | JSON_KEYS('{"a": 1, "b": {"c": 30}}', '$.b') | +----------------------------------------------+ | ["c"] | +----------------------------------------------+
7.JSON_SEARCH(json_doc, one_or_all, search_str[, escape_char[, path] ...])
这个函数是在给定的json_doc范围中搜索指定的search_str的路径(path)。
(1)以下情况会返回null:
任意参数是null
给出的path参数在json_doc中不存在
search_str在json_doc中找不到
(2)one_or_all 参数取值:
'one': 返回第一个匹配到的值的路径。
'all': 返回所有匹配到的值的路径,且路径不重复。如果有多个结果,则以数组形式返回。 并没有规定数组的顺序。
(3)在search_str字符串中,% 和 _ 字符被作为like操作符:%匹配任意数量的字符串(包括0个);_ 匹配一个字符。默认的转义符为 / (如果escape_char没填或者是null),你也可以通过escape_char参数修改转义符(要么填空字符串,要么只能填一个字符)。
mysql> SET @j = '["abc", [{"k": "10"}, "def"], {"x":"abc"}, {"y":"bcd"}]'; mysql> SELECT JSON_SEARCH(@j, 'one', 'abc'); +-------------------------------+ | JSON_SEARCH(@j, 'one', 'abc') | +-------------------------------+ | "$[0]" | +-------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', 'abc'); +-------------------------------+ | JSON_SEARCH(@j, 'all', 'abc') | +-------------------------------+ | ["$[0]", "$[2].x"] | +-------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', 'ghi'); +-------------------------------+ | JSON_SEARCH(@j, 'all', 'ghi') | +-------------------------------+ | NULL | +-------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '10'); +------------------------------+ | JSON_SEARCH(@j, 'all', '10') | +------------------------------+ | "$[1][0].k" | +------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '10', NULL, '$'); +-----------------------------------------+ | JSON_SEARCH(@j, 'all', '10', NULL, '$') | +-----------------------------------------+ | "$[1][0].k" | +-----------------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '10', NULL, '$[*]'); +--------------------------------------------+ | JSON_SEARCH(@j, 'all', '10', NULL, '$[*]') | +--------------------------------------------+ | "$[1][0].k" | +--------------------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '10', NULL, '$**.k'); +---------------------------------------------+ | JSON_SEARCH(@j, 'all', '10', NULL, '$**.k') | +---------------------------------------------+ | "$[1][0].k" | +---------------------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '10', NULL, '$[*][0].k'); +-------------------------------------------------+ | JSON_SEARCH(@j, 'all', '10', NULL, '$[*][0].k') | +-------------------------------------------------+ | "$[1][0].k" | +-------------------------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '10', NULL, '$[1]'); +--------------------------------------------+ | JSON_SEARCH(@j, 'all', '10', NULL, '$[1]') | +--------------------------------------------+ | "$[1][0].k" | +--------------------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '10', NULL, '$[1][0]'); +-----------------------------------------------+ | JSON_SEARCH(@j, 'all', '10', NULL, '$[1][0]') | +-----------------------------------------------+ | "$[1][0].k" | +-----------------------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', 'abc', NULL, '$[2]'); +---------------------------------------------+ | JSON_SEARCH(@j, 'all', 'abc', NULL, '$[2]') | +---------------------------------------------+ | "$[2].x" | +---------------------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '%a%'); +-------------------------------+ | JSON_SEARCH(@j, 'all', '%a%') | +-------------------------------+ | ["$[0]", "$[2].x"] | +-------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '%b%'); +-------------------------------+ | JSON_SEARCH(@j, 'all', '%b%') | +-------------------------------+ | ["$[0]", "$[2].x", "$[3].y"] | +-------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '%b%', NULL, '$[0]'); +---------------------------------------------+ | JSON_SEARCH(@j, 'all', '%b%', NULL, '$[0]') | +---------------------------------------------+ | "$[0]" | +---------------------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '%b%', NULL, '$[2]'); +---------------------------------------------+ | JSON_SEARCH(@j, 'all', '%b%', NULL, '$[2]') | +---------------------------------------------+ | "$[2].x" | +---------------------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '%b%', NULL, '$[1]'); +---------------------------------------------+ | JSON_SEARCH(@j, 'all', '%b%', NULL, '$[1]') | +---------------------------------------------+ | NULL | +---------------------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '%b%', '', '$[1]'); +-------------------------------------------+ | JSON_SEARCH(@j, 'all', '%b%', '', '$[1]') | +-------------------------------------------+ | NULL | +-------------------------------------------+ mysql> SELECT JSON_SEARCH(@j, 'all', '%b%', '', '$[3]'); +-------------------------------------------+ | JSON_SEARCH(@j, 'all', '%b%', '', '$[3]') | +-------------------------------------------+ | "$[3].y" | +-------------------------------------------+