mysql 按天分区答案

【问题标题】：mysql partitioning by daymysql 按天分区
【发布时间】：2012-04-24 09:20:14
【问题描述】：

您好，我想为我的表添加分区。过去 7 天的多媒体数据表记录所以我想创建 7 个分区，一个分区 - 一天所以尝试执行此迁移：

def up
execute "ALTER TABLE multimedia 
  partition by range (to_days(created_at))
  ( 
    PARTITION p0 VALUES LESS THAN (to_days(#{Time.now - (7 * 24 * 60 * 60)})),
    PARTITION p1 VALUES LESS THAN (to_days(#{Time.now - (6 * 24 * 60 * 60)})),
    PARTITION p2 VALUES LESS THAN (to_days(#{Time.now - (5 * 24 * 60 * 60)})),
    PARTITION p3 VALUES LESS THAN (to_days(#{Time.now - (4 * 24 * 60 * 60)})),
    PARTITION p4 VALUES LESS THAN (to_days(#{Time.now - (3 * 24 * 60 * 60)})),
    PARTITION p5 VALUES LESS THAN (to_days(#{Time.now - (2 * 24 * 60 * 60)})),
    PARTITION p6 VALUES LESS THAN (to_days(#{Time.now - (1 * 24 * 60 * 60)})),
    PARTITION p7 VALUES LESS THAN (to_days(#{Time.now - (0 * 24 * 60 * 60)})),
    PARTITION p8 VALUES LESS THAN MAXVALUE 
  );"
end

迁移的结果如下错误：

An error has occurred, all later migrations canceled:

Mysql2::Error: You have an error in your SQL syntax; check the manual that  corresponds     to your MySQL server version for the right syntax to use near 
'11:09:43 +0200)),
     PARTITION p1 VALUES LESS THAN (to_days(2012-04-18 11:0' at line 4: ALTER TABLE  multimedia                        
    partition by range (to_days(created_at))
    ( 

  ==  AddPartitionToMultimedia: migrating =======================================
 -- 
  execute("ALTER TABLE multimedia \n      
partition by range (to_days(created_at))\n      
( \n        
PARTITION p0 VALUES LESS THAN (to_days(2012-04-17 11:09:43 +0200)),\n        
PARTITION p1 VALUES LESS THAN (to_days(2012-04-18 11:09:43 +0200)),\n        
PARTITION p2 VALUES LESS THAN (to_days(2012-04-19 11:09:43 +0200)),\n        
PARTITION p3 VALUES LESS THAN (to_days(2012-04-20 11:09:43 +0200)),\n        
PARTITION p4 VALUES LESS THAN (to_days(2012-04-21 11:09:43 +0200)),\n        
PARTITION p5 VALUES LESS THAN (to_days(2012-04-22 11:09:43 +0200)),\n        
PARTITION p6 VALUES LESS THAN (to_days(2012-04-23 11:09:43 +0200)),\n        
PARTITION p7 VALUES LESS THAN (to_days(2012-04-24 11:09:43 +0200)),\n        
PARTITION p8 VALUES LESS THAN MAXVALUE \n      
);")

【问题讨论】：

错误是：发生错误，所有以后的迁移都取消了：Mysql2::Error: You have an error in your SQL syntax;检查与您的 MySQL 服务器版本相对应的手册，以了解在附近使用的正确语法：
'11:09:43 +0200)), PARTITION p1 VALUES LESS THAN (to_days(2012-04-18 11:0' at line 4: ALTER TABLE 按范围划分多媒体分区 (to_days(created_at )) ('

标签： mysql ruby-on-rails migration partitioning

【解决方案1】：

to_days 函数存在错误。您需要确保传递给 to_days 的值是字符串类型。类似于下面的代码：

to_days('2012-04-17 11:09:43 +0200')
        ^                         ^
        |                         |

【讨论】：