mysql支持原生json使用说明
正文
MySQL在5.7.8开始对json原生支持，本文将对MySQL中json类型的用法简单说明，但愿对你有用。php
CREATE TABLE testproject (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`skill` JSON NOT NULL,
`student` JSON NOT NULL,
PRIMARY KEY (`id`)
);复制代码
查看表结构：html
这样JSON的字段就被建立好了前端
注：JSON类型不能有默认值。vue
插入JSON
插入 json 格式的字符串，能够是对象的形式，也能够是数组的形式，java
INSERT INTO `testproject` (student, skill) VALUES ('{"id": 1, "name": "ggjg"}', '["java", "go", "vue"]');
INSERT INTO `testproject` (student, skill) VALUES ('{"id": 5, "name": "guogege"}', '[]');复制代码
插入json时，数据库会对json作校验，不符合json规范就会报错。python
查询JSON：
查询 json 中的数据用 column->path 的形式，其中对象类型 path 这样表示 $.path, 而数组类型则是 $[index]mysql
查询testproject表student字段中json对象id为1的记录：面试
SELECT * FROM testproject WHERE student->'$.id'= 1;复制代码
查询testproject表student字段中json对象id为1或者5的记录：spring
SELECT * FROM testproject WHERE student->'$.id' in (1,5);
SELECT * FROM testproject WHERE student->'$.id' = 1 or student->'$.id' = 5;复制代码
也能够用函数json_extract：sql
column->path方法有限制，数据源必须是表字段，不然就报错：
如下这样查询，查出来student->'$.name'包含双引号：
SELECT id, student->'$.id', student->'$.name', skill->'$[0]', skill->'$[2]' FROM testproject;复制代码
这不是咱们想要的，能够用 JSONUNQUOTE 函数将双引号去掉，从 MySQL 5.7.13 起也能够经过这个操做符 ->> 这个和 JSONUNQUOTE 是等价的。
由于 JSON 不一样于字符串，因此若是用字符串和 JSON 字段比较，是不会相等的：
mysql> SELECT * FROM testproject WHERE student = '{"id": 1, "name": "ggjg"}';
Empty set (0.00 sec)复制代码
此时能够经过 CAST 将字符串转成 JSON 的形式：
mysql> SELECT * FROM testproject WHERE student = CAST('{"id": 1, "name": "ggjg"}' as JSON);
+----+-----------------------+---------------------------+
| id | skill | student |
+----+-----------------------+---------------------------+
| 10 | ["java", "go", "vue"] | {"id": 1, "name": "ggjg"} |
+----+-----------------------+---------------------------+
1 row in set (0.01 sec)复制代码
要特别注意的是，JSON 中的元素搜索是严格区分变量类型的，好比说整型和字符串是严格区分的：
mysql> SELECT * FROM testproject WHERE student->'$.id' = '1';
Empty set (0.00 sec)
mysql>
mysql> SELECT * FROM testproject WHERE student->'$.id' = 1;
+----+-----------------------+---------------------------+
| id | skill | student |
+----+-----------------------+---------------------------+
| 10 | ["java", "go", "vue"] | {"id": 1, "name": "ggjg"} |
+----+-----------------------+---------------------------+
1 row in set (0.00 sec)复制代码
能够看到搜索字符串 1 和整型 1 的结果是不同的。
除了用以上 column->path 的形式搜索，还能够用JSONCONTAINS 函数，但和 column->path 的形式有点相反的是，JSONCONTAINS 第二个参数是不接受整数的，不管 json 元素是整型仍是字符串，不然会出现这个错误：
mysql> SELECT * FROM testproject WHERE JSON_CONTAINS(student, 1, '$.id');
ERROR 3146 (22032): Invalid data type for JSON data in argument 2 to function json_contains; a JSON string or JSON type is required.
mysql>复制代码
这里必需要使用字符串：
mysql> SELECT * FROM testproject WHERE JSON_CONTAINS(student, '1', '$.id');
+----+-----------------------+---------------------------+
| id | skill | student |
+----+-----------------------+---------------------------+
| 10 | ["java", "go", "vue"] | {"id": 1, "name": "ggjg"} |
+----+-----------------------+---------------------------+
1 row in set (0.00 sec)复制代码
对于数组类型的 JSON 的查询，好比说 skill 中包含有 3 的数据，一样要用 JSON_CONTAINS 函数，一样第二个参数也须要是字符串：
mysql> SELECT * FROM testproject WHERE JSON_CONTAINS(skill, '"go"');
+----+-----------------------+---------------------------+
| id | skill | student |
+----+-----------------------+---------------------------+
| 10 | ["java", "go", "vue"] | {"id": 1, "name": "ggjg"} |
+----+-----------------------+---------------------------+
1 row in set (0.00 sec)
mysql> SELECT * FROM testproject WHERE JSON_CONTAINS(skill, '1');
+----+-----------+------------------------------+
| id | skill | student |
+----+-----------+------------------------------+
| 12 | [1, 2, 3] | {"id": 4, "name": "guogege"} |
+----+-----------+------------------------------+
1 row in set (0.00 sec)复制代码
更新数据
MySQL 并不支持 column->path 的形式进行更新操做。
若是是整个 json 更新的话，和插入时相似的：
mysql> select * from testproject where id = 10;
+----+-----------------------+---------------------------+
| id | skill | student |
+----+-----------------------+---------------------------+
| 10 | ["java", "go", "vue"] | {"id": 1, "name": "ggjg"} |
+----+-----------------------+---------------------------+
1 row in set (0.00 sec)
mysql> UPDATE testproject SET skill = '["js", "java"]' WHERE id = 10;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from testproject where id = 10;
+----+----------------+---------------------------+
| id | skill | student |
+----+----------------+---------------------------+
| 10 | ["js", "java"] | {"id": 1, "name": "ggjg"} |
+----+----------------+---------------------------+
1 row in set (0.00 sec)复制代码
jsonarrayappend和jsonarrayinsert函数使用：
jsonarrayappend是在json后面追加；
jsonarrayinsert是在指定下标插入。
mysql> select * from testproject;
+----+----------------+------------------------------+
| id | skill | student |
+----+----------------+------------------------------+
| 10 | ["js", "java"] | {"id": 1, "name": "ggjg"} |
| 11 | [] | {"id": 5, "name": "guogege"} |
| 12 | [1, 2, 3] | {"id": 4, "name": "guogege"} |
+----+----------------+------------------------------+
3 rows in set (0.00 sec)
mysql> SELECT json_array_append(skill, '$', 'c') from testproject;
+------------------------------------+
| json_array_append(skill, '$', 'c') |
+------------------------------------+
| ["js", "java", "c"] |
| ["c"] |
| [1, 2, 3, "c"] |
+------------------------------------+
3 rows in set (0.00 sec)
mysql> SELECT json_array_insert(skill, '$[1]', 'php') from testproject;
+-----------------------------------------+
| json_array_insert(skill, '$[1]', 'php') |
+-----------------------------------------+
| ["js", "php", "java"] |
| ["php"] |
| [1, "php", 2, 3] |
+-----------------------------------------+
3 rows in set (0.00 sec)
mysql>复制代码
jsonreplace、jsonset、jsoninsert和jsonremove函数用法：
json_replace：只替换已经存在的旧值，不存在则忽略；
json_set：替换旧值，并插入不存在的新值；
json_insert：插入新值，但不替换已经存在的旧值；
json_remove() 删除元素。
json_replace：
mysql> select * from testproject;
+----+----------------+--------------------------------+
| id | skill | student |
+----+----------------+--------------------------------+
| 10 | ["js", "java"] | {"id": 1, "name": "smallsoup"} |
| 11 | [] | {"id": 5, "name": "guogege"} |
| 12 | [1, 2, 3] | {"id": 4, "name": "guogege"} |
+----+----------------+--------------------------------+
3 rows in set (0.00 sec)
mysql>
mysql> UPDATE testproject SET student->'$.name' = 'smallsoup' where student->'$.id' = 1;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server versio
n for the right syntax to use near '->'$.name' = 'smallsoup' where student->'$.id' = 1' at line 1
mysql>
mysql> UPDATE testproject SET student = json_replace(student, '$.name', 'soup') WHERE student->'$.id' = 1;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from testproject;
+----+----------------+------------------------------+
| id | skill | student |
+----+----------------+------------------------------+
| 10 | ["js", "java"] | {"id": 1, "name": "soup"} |
| 11 | [] | {"id": 5, "name": "guogege"} |
| 12 | [1, 2, 3] | {"id": 4, "name": "guogege"} |
+----+----------------+------------------------------+
3 rows in set (0.00 sec)复制代码
json_set：
mysql> select * from testproject;
+----+----------------+------------------------------+
| id | skill | student |
+----+----------------+------------------------------+
| 10 | ["js", "java"] | {"id": 1, "name": "soup"} |
| 11 | [] | {"id": 5, "name": "guogege"} |
| 12 | [1, 2, 3] | {"id": 4, "name": "guogege"} |
+----+----------------+------------------------------+
3 rows in set (0.00 sec)
mysql> UPDATE testproject SET student = json_set(student, '$.name', 'small', '$.age', 22) WHERE student->'$.id'= 1;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from testproject;
+----+----------------+---------------------------------------+
| id | skill | student |
+----+----------------+---------------------------------------+
| 10 | ["js", "java"] | {"id": 1, "age": 22, "name": "small"} |
| 11 | [] | {"id": 5, "name": "guogege"} |
| 12 | [1, 2, 3] | {"id": 4, "name": "guogege"} |
+----+----------------+---------------------------------------+
3 rows in set (0.00 sec)复制代码
json_insert：
mysql> select * from testproject;
+----+----------------+---------------------------------------+
| id | skill | student |
+----+----------------+---------------------------------------+
| 10 | ["js", "java"] | {"id": 1, "age": 22, "name": "small"} |
| 11 | [] | {"id": 5, "name": "guogege"} |
| 12 | [1, 2, 3] | {"id": 4, "name": "guogege"} |
+----+----------------+---------------------------------------+
3 rows in set (0.00 sec)
mysql> UPDATE testproject SET student = json_insert(student, '$.name', 'soup', '$.addr', '苏州') WHERE student->'$.id'=
1;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from testproject;
+----+----------------+---------------------------------------------------------+
| id | skill | student |
+----+----------------+---------------------------------------------------------+
| 10 | ["js", "java"] | {"id": 1, "age": 22, "addr": "苏州", "name": "small"} |
| 11 | [] | {"id": 5, "name": "guogege"} |
| 12 | [1, 2, 3] | {"id": 4, "name": "guogege"} |
+----+----------------+---------------------------------------------------------+
3 rows in set (0.00 sec)复制代码
json_remove() :
mysql> select * from testproject;
+----+----------------+---------------------------------------------------------+
| id | skill | student |
+----+----------------+---------------------------------------------------------+
| 10 | ["js", "java"] | {"id": 1, "age": 22, "addr": "苏州", "name": "small"} |
| 11 | [] | {"id": 5, "name": "guogege"} |
| 12 | [1, 2, 3] | {"id": 4, "name": "guogege"} |
+----+----------------+---------------------------------------------------------+
3 rows in set (0.00 sec)
mysql> UPDATE testproject SET student = json_remove(student, '$.name', '$.age') WHERE student->'$.id' = 1;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from testproject;
+----+----------------+------------------------------+
| id | skill | student |
+----+----------------+------------------------------+
| 10 | ["js", "java"] | {"id": 1, "addr": "苏州"} |
| 11 | [] | {"id": 5, "name": "guogege"} |
| 12 | [1, 2, 3] | {"id": 4, "name": "guogege"} |
+----+----------------+------------------------------+
3 rows in set (0.00 sec)复制代码
能够看到name和age就被移除了。
以上只列出了部分函数的说明，mysql官方提供的函数列表以下：
更多用法请查看官方文档：
https://dev.mysql.com/doc/refman/5.7/en/json-function-reference.html
本公众号免费提供csdn下载服务，海量IT学习资源，若是你准备入IT坑，励志成为优秀的程序猿，那么这些资源很适合你，包括但不限于java、go、python、springcloud、elk、嵌入式 、大数据、面试资料、前端 等资源。同时咱们组建了一个技术交流群，里面有不少大佬，会不定时分享技术文章，若是你想来一块儿学习提升，能够公众号后台回复【2】，免费邀请加技术交流群互相学习提升，会不按期分享编程IT相关资源。
扫码关注，精彩内容第一时间推给你
相关文章
- 1. SQL Server 2016 JSON原生支持实例说明
- 2. SQL Server2016 原生支持JSON
- 3. Mysql5.7.9原生JSON格式支持
- 4. mysql5.7原生支持json格式
- 5. XtraBackup应用说明（支持TokuDB） XtraBackup 安装使用 XtraBackup 使用说明
- 6. MySQL使用说明
- 7. Configure脚本支持说明
- 8. #MySQL 5.7.8 支持Json类型
- 9. JSON Web Token（JWT）使用步骤说明
- 10. 六、json支持
- 更多相关文章...
- • PHP EOF(heredoc) 使用说明 - PHP教程
- • Eclipse 窗口说明 - Eclipse 教程
- • Java Agent入门实战（三）-JVM Attach原理与使用
- • Composer 安装与使用
相关标签/搜索
每日一句
-
每一个你不满意的现在，都有一个你没有努力的曾经。
欢迎关注本站公众号,获取更多信息
