mysql - 将 Mysql 列默认值更改为 CURRENT_DATE 会出现错误？

Question

ALTER TABLE `mysystem`.`projects` 
MODIFY COLUMN `project_capture_date` DATE NOT NULL DEFAULT CURRENT_DATE();

给出:

Error Code: 1064. 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 'CURRENT_DATE()'
 at line 2

当前行定义:

project_capture_date, date, NO, , 0000-00-00

最近刚刚将引擎从 MyISAM 更改为 InnoDB。

Answer 1

根据mysql文档

http://dev.mysql.com/doc/refman/5.0/en/data-type-defaults.html

The DEFAULT value clause in a data type specification indicates a default value for a column. With one exception, the default value must be a constant; it cannot be a function or an expression. This means, for example, that you cannot set the default for a date column to be the value of a function such as NOW() or CURRENT_DATE. The exception is that you can specify CURRENT_TIMESTAMP as the default for a TIMESTAMP

要解决此问题，您可能需要将数据类型定义为带有 DEFAULT CURRENT_TIMESTAMP 的 TIMESTAMP 列

<强> DEMO

如果您不需要 TIMESTAMP，则可以在插入时将列值设置为 Now()