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。

原文地址：http://blog.51cto.com/wujianwei/2296662