修改 MySql 中的列长度

Question

我正在发出以下命令：

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

目前是 VARCHAR(1024)，但我收到此错误：

Error Code: 1265 Data truncated for column mysql

我猜这是因为某些行的长度超过了 1022 个字符。当我将 IGNORE 添加到命令时，命令成功完成但这些行仍然有 1024 个字符，mysql 没有删除最后 2 个字符以使其成为 1022，有什么方法可以强制执行此操作以便确保所有行都以新的列大小结束？

这是我的 table:

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 服务器是 SQL strict mode 中的运行。

提到此模式对 ALTER TABLE 执行的影响：

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

我会尝试在运行时根据 this 更改 SQL 模式（您可能需要 SUPER 权限 - 不确定）：

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';

然后重复您的 ALTER 语句。

修改 MySql 中的列长度

Modify column length in MySql

mysql

innodb

alter-table

truncated