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业务数据量比较大的时候,可能对数据按月建表。随之而来的是每月都需要创建对应表结构。如果忘记了,恐怕对业务影响比较大吧!这种表结构的特点:表字段全部相同,索引也是一致的,表的名称随着月份自动变化。
步骤:
1、创建存储过程
2、创建定时任务(需要开启全局的event_scheduler)
1 DELIMITER $$ 2 3 4 DROP PROCEDURE IF EXISTS `pro_autocre_month_table`$$ 5 6 CREATE DEFINER=`root`@`%` PROCEDURE `pro_autocre_month_table`() 7 BEGIN 8 DECLARE old_table_name VARCHAR(128); 9 DECLARE new_table_name VARCHAR(128);10 DECLARE done INT DEFAULT 0;11 12 DECLARE table_cursor CURSOR FOR SELECT TABLE_NAME FROM `information_schema`.`TABLES` WHERE TABLE_SCHEMA = '****' AND TABLE_NAME REGEXP DATE_FORMAT(CURDATE(), '%Y%m');13 DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET done = 1; 14 15 OPEN table_cursor; 16 REPEAT17 18 FETCH table_cursor INTO old_table_name;19 IF NOT done THEN 20 21 SELECT REPLACE(old_table_name,DATE_FORMAT(CURDATE(), '%Y%m'),DATE_FORMAT(DATE_ADD(CURDATE(),INTERVAL 1 MONTH), '%Y%m')) INTO new_table_name;22 SET @sqlCmd = CONCAT('create table if not exists `',new_table_name,'` like `' , old_table_name,'`');23 PREPARE preStmt FROM @sqlCmd; 24 EXECUTE preStmt;25 END IF ;26 UNTIL done END REPEAT;27 CLOSE table_cursor;28 END$$29 30 DELIMITER ;31 -- ---------------------------------------------------------------------32 DELIMITER $$33 34 SET GLOBAL event_scheduler = ON$$ 35 36 CREATE /*[DEFINER = { user | CURRENT_USER }]*/ EVENT `test`.`auto_create_table`37 38 ON SCHEDULE39 ON SCHEDULE EVERY 1 WEEK STARTS '2014-01-01 00:00:00' ON COMPLETION NOT PRESERVE ENABLE 40 DO BEGIN41 CALL pro_autocre_month_table();42 END$$43 44 DELIMITER ;
备注:
1、请将“ TABLE_SCHEMA = '****'”中的"****"修改为表所在的数据库的名称
2、该sql 会对数据库下表名称为:201401这种类型的表结构有效。其它类型的结构可参考下面的说明:
Specifier | Description |
---|---|
%a | Abbreviated weekday name (Sun ..Sat ) |
%b | Abbreviated month name (Jan ..Dec ) |
%c | Month, numeric (0 ..12 ) |
%D | Day of the month with English suffix (0th , 1st , 2nd , 3rd , …) |
%d | Day of the month, numeric (00 ..31 ) |
%e | Day of the month, numeric (0 ..31 ) |
%f | Microseconds (000000 ..999999 ) |
%H | Hour (00 ..23 ) |
%h | Hour (01 ..12 ) |
%I | Hour (01 ..12 ) |
%i | Minutes, numeric (00 ..59 ) |
%j | Day of year (001 ..366 ) |
%k | Hour (0 ..23 ) |
%l | Hour (1 ..12 ) |
%M | Month name (January ..December ) |
%m | Month, numeric (00 ..12 ) |
%p | AM or PM |
%r | Time, 12-hour (hh:mm:ss followed by AM or PM ) |
%S | Seconds (00 ..59 ) |
%s | Seconds (00 ..59 ) |
%T | Time, 24-hour (hh:mm:ss ) |
%U | Week (00 ..53 ), where Sunday is the first day of the week; mode 0 |
%u | Week (00 ..53 ), where Monday is the first day of the week; mode 1 |
%V | Week (01 ..53 ), where Sunday is the first day of the week; mode 2; used with %X |
%v | Week (01 ..53 ), where Monday is the first day of the week; mode 3; used with %x |
%W | Weekday name (Sunday ..Saturday ) |
%w | Day of the week (0 =Sunday..6 =Saturday) |
%X | Year for the week where Sunday is the first day of the week, numeric, four digits; used with %V |
%x | Year for the week, where Monday is the first day of the week, numeric, four digits; used with %v |
%Y | Year, numeric, four digits |
%y | Year, numeric (two digits) |
%% | A literal “% ” character |
% | x , for any “x ” not listed above |
3、计划任务、存储过程、游标 不熟悉的,请参考官方文档。
4、如果怕定时任务执行失败,可以每半个月执行一次。这样能防止第一次执行失败!
5、oracle、sql server 也有对应的管理数据库,可通过类似方法创建表结构
6、请确保用户有访问information_schema数据库的权限
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