MariaDB10.2.X-新特性2-支持check约束and with as

前几天写了一篇MariaDB10.2支持分析函数，大家印象中MySQL不支持with as ，check约束，那么MariaDB10.2也同样给你惊喜

1.with as

MariaDB [test11]> with a as ( select * from t1 where channerId ='支付宝' )  select * from a;

+----+--------+------------+-----------+--------+

| id | userId | orderId    | channerId | amount |

+----+--------+------------+-----------+--------+

|  1 | 张3    | 2016060101 | 支付宝    |    100 |

|  2 | 李4    | 2016060102 | 支付宝    |     98 |

|  7 | 张3    | 2016060107 | 支付宝    |    200 |

| 10 | 李4    | 2016060110 | 支付宝    |    300 |

+----+--------+------------+-----------+--------+

4 rows in set (0.01 sec)

MariaDB [test11]> explain with a as ( select * from t1 where channerId ='支付宝' )  select * from a;

+------+-------------+-------+------+---------------+---------------+---------+-------+------+-----------------------+

| id   | select_type | table | type | possible_keys | key           | key_len | ref   | rows | Extra                 |

+------+-------------+-------+------+---------------+---------------+---------+-------+------+-----------------------+

|    1 | SIMPLE      | t1    | ref  | idx_channerId | idx_channerId | 182     | const |    4 | Using index condition |

+------+-------------+-------+------+---------------+---------------+---------+-------+------+-----------------------+

1 row in set (0.00 sec)

MariaDB [test11]>

#check 约束

MariaDB [test11]> CREATE TABLE `t_user` (

-> `id`  int NOT NULL AUTO_INCREMENT ,

-> `name`  varchar(255) NOT NULL DEFAULT '' ,

-> `age`  tinyint UNSIGNED NULL check(age > 0 and age < 120)  ,

-> `gender`  tinyint NULL COMMENT '(0男，1女，2未知)' ,

-> `address`  varchar(255) NULL ,

-> PRIMARY KEY (`id`)

-> )

-> ;

Query OK, 0 rows affected (0.03 sec)

MariaDB [test11]> insert into t_user  ( name,age,gender,address) values ( 'zhangsan',1,1,'afdadfa');

Query OK, 1 row affected (0.03 sec)

MariaDB [test11]> insert into t_user  ( name,age,gender,address) values ( 'lisi',121,0,'afdadfa');

ERROR 4022 (23000): CONSTRAINT `age` failed for `test11`.`t_user`

MariaDB [test11]> insert into t_user  ( name,age,gender,address) values ( 'lisi',0,0,'afdadfa');

ERROR 4022 (23000): CONSTRAINT `age` failed for `test11`.`t_user`

MariaDB [test11]> update t_user set age =122 where id =1;
ERROR 4022 (23000): CONSTRAINT `age` failed for `test11`.`t_user`
MariaDB [test11]>

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这个很值得期待的版本，希望官方版本也能及时跟进，纵观MySQL5.6,5.7的很多特性都是借鉴MariaDB的特性