修改列长度在MySQL

Question

我发出以下命令：

ALTER TABLE `table_name` MODIFY `column_name` VARCHAR(1022) 

在它的VARCHAR(1024)的那一刻，但我得到这个错误：

Error Code: 1265 Data truncated for column mysql 

我想这是因为某些行超过1022个字符。当我将IGNORE添加到命令中时，命令成功完成，但这些行仍有1024个字符，mysql没有删除最后2个字符以使其成为1022，是否有任何方法强制执行此操作，以确保所有行都以新的列大小？

这是我的表：

CREATE TABLE `e_entity` (
`OID` int(11) NOT NULL AUTO_INCREMENT, 
`E_E_OID` int(11) DEFAULT NULL, 
`UNIQUE_IDX` int(11) NOT NULL, 
`APP_OID` int(11) NOT NULL, 
`META_OID` int(11) NOT NULL, 
`STORE_DATE` datetime NOT NULL, 
`REL_DISPLAY` varchar(1024) NOT NULL, 
`SINDEX01` varchar(1024) NOT NULL, 
`SINDEX02` varchar(1024) NOT NULL, 
`SINDEX03` varchar(1024) NOT NULL, 
`SINDEX04` varchar(1024) NOT NULL, 
`SINDEX05` varchar(1024) NOT NULL, 
`SINDEX06` varchar(1024) NOT NULL, 
`SINDEX07` varchar(1024) NOT NULL, 
`SINDEX08` varchar(1024) NOT NULL, 
`SINDEX09` varchar(1024) NOT NULL, 
`SINDEX10` varchar(1024) NOT NULL, 
`NINDEX01` double NOT NULL, 
`NINDEX02` double NOT NULL, 
`NINDEX03` double NOT NULL, 
`NINDEX04` double NOT NULL, 
`NINDEX05` double NOT NULL, 
`NINDEX06` double NOT NULL, 
`NINDEX07` double NOT NULL, 
`NINDEX08` double NOT NULL, 
`NINDEX09` double NOT NULL, 
`NINDEX10` double NOT NULL, 
`DINDEX01` datetime NOT NULL, 
`DINDEX02` datetime NOT NULL, 
`DINDEX03` datetime NOT NULL, 
`DINDEX04` datetime NOT NULL, 
`DINDEX05` datetime NOT NULL, 
`DINDEX06` datetime NOT NULL, 
`DINDEX07` datetime NOT NULL, 
`DINDEX08` datetime NOT NULL, 
`DINDEX09` datetime NOT NULL, 
`DINDEX10` datetime NOT NULL, 
`FREETEXT` mediumtext NOT NULL, 
`UID` int(11) DEFAULT NULL, 
PRIMARY KEY (`OID`), 
KEY `App_Parent` (`META_OID`), 
KEY `RelDisplay` (`REL_DISPLAY`), 
KEY `sindex01` (`META_OID`,`SINDEX01`(64)), 
KEY `sindex02` (`META_OID`,`SINDEX02`(64)), 
KEY `sindex03` (`META_OID`,`SINDEX03`(64)), 
KEY `sindex04` (`META_OID`,`SINDEX04`(64)), 
KEY `sindex05` (`META_OID`,`SINDEX05`(64)), 
KEY `sindex06` (`META_OID`,`SINDEX06`(64)), 
KEY `sindex07` (`META_OID`,`SINDEX07`(64)), 
KEY `sindex08` (`META_OID`,`SINDEX08`(64)), 
KEY `sindex09` (`META_OID`,`SINDEX09`(64)), 
KEY `sindex10` (`META_OID`,`SINDEX10`(64)), 
KEY `nindex01` (`META_OID`,`NINDEX01`), 
KEY `nindex02` (`META_OID`,`NINDEX02`), 
KEY `nindex03` (`META_OID`,`NINDEX03`), 
KEY `nindex04` (`META_OID`,`NINDEX04`), 
KEY `nindex05` (`META_OID`,`NINDEX05`), 
KEY `dindex01` (`META_OID`,`DINDEX01`), 
KEY `dindex02` (`META_OID`,`DINDEX02`), 
KEY `dindex03` (`META_OID`,`DINDEX03`), 
KEY `dindex04` (`META_OID`,`DINDEX04`), 
KEY `dindex05` (`META_OID`,`DINDEX05`), 
KEY `nindex06` (`META_OID`,`NINDEX06`), 
KEY `nindex07` (`META_OID`,`NINDEX07`), 
KEY `nindex08` (`META_OID`,`NINDEX08`), 
KEY `nindex09` (`META_OID`,`NINDEX09`), 
KEY `nindex10` (`META_OID`,`NINDEX10`), 
KEY `dindex06` (`META_OID`,`DINDEX06`), 
KEY `dindex07` (`META_OID`,`DINDEX07`), 
KEY `dindex08` (`META_OID`,`DINDEX08`), 
KEY `dindex09` (`META_OID`,`DINDEX09`), 
KEY `dindex10` (`META_OID`,`DINDEX10`), 
KEY `E_E_OID` (`E_E_OID`) 
) ENGINE=InnoDB AUTO_INCREMENT=469158 DEFAULT CHARSET=utf8 ROW_FORMAT=COMPRESSED; 

Answer 1

我猜你的MySQL服务器正在运行SQL strict mode。

有许多关于ALTER TABLE执行这种模式的效果奖：

When you change a data type using CHANGE or MODIFY, MySQL tries to convert existing column values to the new type as well as possible.

This conversion may result in alteration of data. For example, if you shorten a string column, values may be truncated. To prevent the operation from succeeding if conversions to the new data type would result in loss of data, enable strict SQL mode before using ALTER TABLE

我想尝试在基于this运行时更改SQL模式（可能需要SUPER权限 - 不知道）：

To change the SQL mode at runtime, set the global or session sql_mode system variable using a SET statement:

SET SESSION sql_mode = 'modes'; 

然后重复你的ALTER语句。