mysql - 实时服务器中当前时间戳字段的默认值无效

Question

下面的查询在我的本地主机上工作正常但是当我尝试在实时服务器上执行这个查询时它给出了 sql 错误

CREATE TABLE IF NOT EXISTS `tbl_claims` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`claimed_profile_id` int(11) NOT NULL,
`claimed_by_profile_id` int(11) NOT NULL COMMENT 'this will be only doctor''s profile id',
`name` varchar(100) NOT NULL,
`email` varchar(100) NOT NULL,
`phone_no` varchar(100) NOT NULL,
`status` enum('approved','disapproved','pending') NOT NULL DEFAULT 'pending',
`added_on` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP, PRIMARY KEY (`id`)
 ) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=4 ;

出现以下错误:

 Invalid default value for 'added_on'

我不知道为什么上面的查询在 loalhost 中运行良好，而在实时服务器中却不能运行。

查询不工作的服务器有 PHP 版本 5.6.33

如有任何建议，我们将不胜感激。

Answer 1

我怀疑这是因为您试图将 CURRENT_TIMESTAMP 用作 datetime 字段的默认值。

For MySQL >= 5.6 :

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 TIMESTAMP and DATETIME columns.

For MySQL <= 5.5 :

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 column.

如您所见，对于 5.5 及以下版本，您只能使用 CURRENT_TIMESTAMP 作为 TIMESTAMP 字段的默认值。