修改列長度在MySQL

Question

我發出以下命令：

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

在它的VARCHAR(1024)的那一刻，但我得到這個錯誤：

Error Code: 1265 Data truncated for column mysql 

我想這是因爲某些行超過1022個字符。當我將IGNORE添加到命令中時，命令成功完成，但這些行仍有1024個字符，mysql沒有刪除最後2個字符以使其成爲1022，是否有任何方法強制執行此操作，以確保所有行都以新的列大小？

這是我的表：

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服務器正在運行SQL strict mode。

有許多關於ALTER TABLE執行這種模式的效果獎：

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

我想嘗試在基於this運行時更改SQL模式（可能需要SUPER權限 - 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'; 

然後重複你的ALTER語句。