使用场景：

主表数据量特别大，为了提高查询的速度，可以考虑按月进行分表，要求就是当月的数据到当月表查询，上月的数据到上月表查询，当天的数据到主表来查询。这样在一定程度上也是提高了数据的查询速度

过程演示：

1.创建总表：

CREATE TABLE `zong_biao` (

`id` int(8) NOT NULL AUTO_INCREMENT,

`username` varchar(20) COLLATE utf8_unicode_ci NOT NULL,

`password` varchar(20) COLLATE utf8_unicode_ci NOT NULL,

`create_time` varchar(20) COLLATE utf8_unicode_ci NOT NULL,

`day` date NOT NULL DEFAULT '0000-00-00' COMMENT '日期',

PRIMARY KEY (`id`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

2.创建定时器：

当前时间1分钟后，每2分钟写入一条数据到zong_biao，为了演示，要保证主表里面一直有数据定时在写入

delimiter $$

create event event_1

on schedule every 2 MINUTE STARTS CURRENT_TIMESTAMP + INTERVAL 1 MINUTE

COMMENT 'xiaowu create'

do

BEGIN

insert into test.zong_biao(username,password,create_time,day) values("李四","tomcat",now(),curdate());

END $$

delimiter ;

3.按月对主表进行分表拆分数据

3.1建立上月表和本月表

mysql> create table biao_lastmonth like zong_biao;

Query OK, 0 rows affected

mysql> create table biao_month like zong_biao;

Query OK, 0 rows affected

3.2.创建一个表来记录是否是1号，数据写入是否成功:

Create Table: CREATE TABLE `dr_call_time` (

`id` int(11) unsigned NOT NULL AUTO_INCREMENT,

`c_datetime` datetime NOT NULL COMMENT '执行时间',

`type` tinyint(4) NOT NULL DEFAULT '0' COMMENT '是否为1号，默认为0，即不是1号',

PRIMARY KEY (`id`)

) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8

mysql> select * from dr_call_time;

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

| id | c_datetime | type |

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

| 1 | 2018-09-24 02:00:00 | 0 |

| 2 | 2018-09-25 02:00:00 | 0 |

| 3 | 2018-09-26 02:00:00 | 0 |

| 4 | 2018-09-27 02:00:00 | 0 |

| 5 | 2018-09-28 02:00:00 | 0 |

| 6 | 2018-09-29 02:00:00 | 0 |

| 7 | 2018-09-30 02:00:00 | 0 |

| 8 | 2018-10-01 02:00:01 | 1 |

| 9 | 2018-10-02 02:00:00 | 0 |

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

9 rows in set (0.00 sec)

3.3. 建立存储过程

/*每月1号 清空上月表，清空本月表；如果不是每月1号，则把昨天的数据插入本月数据表中*/

delimiter //

CREATE PROCEDURE p_dr_stats()

BEGIN

declare v_day int;

declare v_yesterday date;

set v_day = day(curdate());

set v_yesterday = date_sub(current_date(),interval 1 day);

select v_day;

/*select v_yesterday;*/

/*每月第一天 清空本月表和上月表；如果不是本月第一天，则把昨天的数据插入本月数据表中*/

if v_day = 1 then

truncate table biao_lastmonth;

truncate table biao_month;

insert into biao_lastmonth select * from zong_biao where day >= date_add(curdate()-day(curdate())+1,interval -1 month) and day < date_add(curdate(), interval - day(curdate()) + 1 day);

insert into dr_call_time(c_datetime,type) values(now(),1); /* 用于记录该过程是否已执行*/

else

insert into biao_month select * from zong_biao where day >= v_yesterday and day < curdate();

insert into dr_call_time(c_datetime) values(now());

end if;

end //

delimiter ;

3.4 建立定时任务event

/*从2018-09-24 02:00:00开始，每天凌晨2:00执行上面的3.3的存储过程

delimiter //

CREATE EVENT e_test

ON SCHEDULE EVERY 1 day STARTS TIMESTAMP '2018-09-24 02:00:00'

ON COMPLETION PRESERVE

DO

BEGIN

CALL p_dr_stats();

END//

delimiter ;

查看记录是否是1号的表，了解event定时器和储存过程的执行状态

mysql> select * from dr_call_time;

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

| id | c_datetime | type |

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

| 1 | 2018-09-24 02:00:00 | 0 |

| 2 | 2018-09-25 02:00:00 | 0 |

| 3 | 2018-09-26 02:00:00 | 0 |

| 4 | 2018-09-27 02:00:00 | 0 |

| 5 | 2018-09-28 02:00:00 | 0 |

| 6 | 2018-09-29 02:00:00 | 0 |

| 7 | 2018-09-30 02:00:00 | 0 |

| 8 | 2018-10-01 02:00:01 | 1 |

| 9 | 2018-10-02 02:00:00 | 0 |

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

9 rows in set (0.00 sec)

到此处演示完毕，测试都是没问题的。

3.5查看创建存储过程的语句

mysql> show create procedure p_dr_stats\G

*************************** 1. row ***************************

Procedure: p_dr_stats

sql_mode: STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION

Create Procedure: CREATE DEFINER=`root`@`localhost` PROCEDURE `p_dr_stats`()

BEGIN

declare v_day int;

declare v_yesterday date;

set v_day = day(curdate());

set v_yesterday = date_sub(current_date(),interval 1 day);

select v_day;

if v_day = 1 then

truncate table biao_lastmonth;

truncate table biao_month;

insert into biao_lastmonth select * from zong_biao where day >= date_add(curdate()-day(curdate())+1,interval -1 month) and day < date_add(curdate(), interval - day(curdate()) + 1 day);

insert into dr_call_time(c_datetime,type) values(now(),1);

else

insert into biao_month select * from zong_biao where day >= v_yesterday and day < curdate();

insert into dr_call_time(c_datetime) values(now());

end if;

end

character_set_client: utf8

collation_connection: utf8_general_ci

Database Collation: utf8_general_ci

1 row in set (0.00 sec)

mysql>

到此处MySQL之按月拆分主表并按月分表写入数据已经演示完毕了，欢迎伙伴们留言一起交流学习。