![wKioL1ftzemTuZrlAAA4eVx2Dz8486.jpg]( "图标2.JPG")
Part1:JSON格式的支持
MySQL5.7版本终于支持了原生的JSON格式,即将关系型数据库和文档型NO_SQL数据库集于一身。本文接下来将对这特性分别就MySQL5.7和MariaDB10.1各自实现的方法异同进行介绍和演示。
Part2:创建相应表结构
[root@HE3 ~]# mysql -V
mysql Ver 14.14 Distrib 5.7.15, for linux-glibc2.5 (x86_64) using EditLine wrapper
mysql> create database helei;
Query OK, 1 row affected (0.00 sec)
mysql> use helei;
Database changed
mysql> create table helei (id int(10) unsigned NOT NULL,context json default null,primary key(id));
Query OK, 0 rows affected (0.02 sec)
mysql> show create table helei \G
*************************** 1. row ***************************
Table: helei
Create Table: CREATE TABLE `helei` (
`id` int(10) unsigned NOT NULL,
`context` json DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0.02 sec)
Part3:构造数据&测试
mysql> desc helei;
+---------+------------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+---------+------------------+------+-----+---------+-------+
| id | int(10) unsigned | NO | PRI | NULL | |
| context | json | YES | | NULL | |
+---------+------------------+------+-----+---------+-------+
2 rows in set (0.00 sec)
mysql> insert into helei values(1,'{"name":"贺磊","age":100}'),(2,'{"name":"陈加持","age":30}'),(3,'{"name":"于浩","age":28}');
Query OK, 3 rows affected (0.00 sec)
Records: 3 Duplicates: 0 Warnings: 0
mysql> select * from helei;
+----+----------------------------------+
| id | context |
+----+----------------------------------+
| 1 | {"age": 100, "name": "贺磊"} |
| 2 | {"age": 30, "name": "陈加持"} |
| 3 | {"age": 28, "name": "于浩"} |
+----+----------------------------------+
3 rows in set (0.00 sec)
mysql> select id,JSON_EXTRACT(context,'$.name') name,JSON_EXTRACT(context,'$.age') age from helei;
+----+-------------+------+
| id | name | age |
+----+-------------+------+
| 1 | "贺磊" | 100 |
| 2 | "陈加持" | 30 |
| 3 | "于浩" | 28 |
+----+-------------+------+
3 rows in set (0.00 sec)
获取Key-Value
mysql> select id,json_keys(context) from helei;
+----+--------------------+
| id | json_keys(context) |
+----+--------------------+
| 1 | ["age", "name"] |
| 2 | ["age", "name"] |
| 3 | ["age", "name"] |
+----+--------------------+
3 rows in set (0.00 sec)
获取全部Key
mysql> update helei set context=JSON_INSERT(context,'$.name',"贺磊",'$.address','beijing')where id=1;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from helei;
+----+------------------------------------------------------+
| id | context |
+----+------------------------------------------------------+
| 1 | {"age": 100, "name": "贺磊", "address": "beijing"} |
| 2 | {"age": 30, "name": "陈加持"} |
| 3 | {"age": 28, "name": "于浩"} |
+----+------------------------------------------------------+
3 rows in set (0.00 sec)
增加Key-Value
mysql> update helei set context=JSON_SET(context,'$.name',"高穷帅")where id=1;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from helei;
+----+---------------------------------------------------------+
| id | context |
+----+---------------------------------------------------------+
| 1 | {"age": 100, "name": "高穷帅", "address": "beijing"} |
| 2 | {"age": 30, "name": "陈加持"} |
| 3 | {"age": 28, "name": "于浩"} |
+----+---------------------------------------------------------+
3 rows in set (0.00 sec)
变更key-value
mysql> update helei set context=JSON_REMOVE(context,'$.name') where id=1;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> select * from helei;
+----+------------------------------------+
| id | context |
+----+------------------------------------+
| 1 | {"age": 100, "address": "beijing"} |
| 2 | {"age": 30, "name": "陈加持"} |
| 3 | {"age": 28, "name": "于浩"} |
+----+------------------------------------+
3 rows in set (0.00 sec)
删除Key-Value
JSON格式存储BLOB的测试
Part1:Dynamic Columns处理方式的异同
①MySQL5.7的动态列JSON格式存储
mysql> insert into helei_blob values(1,'{"name":"贺磊","age":100}'),(2,'{"name":"陈加持","age":30}'),(3,'{"name":"于浩","age":28}');
Query OK, 3 rows affected (0.01 sec)
Records: 3 Duplicates: 0 Warnings: 0
mysql> select * from helei_blob;
+----+-------------------------------+
| id | blob_col |
+----+-------------------------------+
| 1 | {"name":"贺磊","age":100} |
| 2 | {"name":"陈加持","age":30} |
| 3 | {"name":"于浩","age":28} |
+----+-------------------------------+
3 rows in set (0.00 sec)
②MariaDB的动态列JSON格式存储
MariaDB [helei]> create table helei (id int(10) unsigned NOT NULL,context json default null,primary key(id));
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'json default null,primary key(id))' at line 1
可以看到MariaDB并不能直接存储JSON类型。
MariaDB [helei]> show create table helei_blob\G;
*************************** 1. row ***************************
Table: helei_blob
Create Table: CREATE TABLE `helei_blob` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`blob_col` blob,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0.00 sec)
ERROR: No query specified
MariaDB [helei]> insert into helei_blob values(5,column_create('color','blue','size','XL'));
Query OK, 1 row affected (0.01 sec)
MariaDB [helei]> select * from helei_blob;
+----+--------------------------------+
| id | blob_col |
+----+--------------------------------+
| 1 | {"name":"贺磊","age":100} |
| 2 | {"name":"陈加持","age":30} |
| 3 | {"name":"于浩","age":28} |
| 5 | 3 sizecolor!XL!blue |
+----+--------------------------------+
4 rows in set (0.00 sec)
直接查询是乱码需用以下函数查询
MariaDB [helei]> select id,column_json(blob_col) from helei_blob where id =5;
+----+------------------------------+
| id | column_json(blob_col) |
+----+------------------------------+
| 5 | {"size":"XL","color":"blue"} |
+----+------------------------------+
1 row in set (0.00 sec)
MariaDB [helei]> select id,column_list(blob_col) from helei_blob where id =5;
+----+-----------------------+
| id | column_list(blob_col) |
+----+-----------------------+
| 5 | `size`,`color` |
+----+-----------------------+
1 row in set (0.00 sec)
获取全部Key
MariaDB [helei]> select id,column_get(blob_col,'color' as char) as color from helei_blob where id =5;
+----+-------+
| id | color |
+----+-------+
| 5 | blue |
+----+-------+
1 row in set (0.00 sec)
获取Key-Value
MariaDB [helei]> update helei_blob set blob_col=column_add(blob_col,'sex','man') where id=5;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
MariaDB [helei]> select id,column_json(blob_col) from helei_blob where id=5;
+----+------------------------------------------+
| id | column_json(blob_col) |
+----+------------------------------------------+
| 5 | {"sex":"man","size":"XL","color":"blue"} |
+----+------------------------------------------+
1 row in set (0.00 sec)
增加Key-Value
MariaDB [helei]> update helei_blob set blob_col=column_add(blob_col,'color','black') where id=5;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
MariaDB [helei]> select id,column_json(blob_col) from helei_blob where id=5;
+----+-------------------------------------------+
| id | column_json(blob_col) |
+----+-------------------------------------------+
| 5 | {"sex":"man","size":"XL","color":"black"} |
+----+-------------------------------------------+
1 row in set (0.00 sec)
更改Key-Value
MariaDB [helei]> update helei_blob set blob_col=column_delete(blob_col,'sex','man') where id=5;
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
MariaDB [helei]> select id,column_json(blob_col) from helei_blob where id=5;
+----+-------------------------------+
| id | column_json(blob_col) |
+----+-------------------------------+
| 5 | {"size":"XL","color":"black"} |
+----+-------------------------------+
1 row in set (0.00 sec)
删除Key-Value
——总结——
虽然MySQL5.7和MariaDB10.0/10.1版本对于JSON的支持是比较完整的,不过MongoDB的Sharding功能更加好用,个人更倾向于MongoDB。由于笔者的水平有限，编写时间也很仓促，文中难免会出现一些错误或者不准确的地方，不妥之处恳请读者批评指正。
