MySQL:TIMESTAMP的无效默认值 [英] MySQL: Invalid default value for TIMESTAMP
本文介绍了MySQL:TIMESTAMP的无效默认值的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我得到了错误
ERROR 1067 (42000) at line 5459: Invalid default value for 'start_time'
运行以下查询时
DROP TABLE IF EXISTS `slow_log`;
CREATE TABLE IF NOT EXISTS `slow_log` (
`start_time` timestamp(6) NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`user_host` mediumtext NOT NULL,
`query_time` time(6) NOT NULL,
`lock_time` time(6) NOT NULL,
`rows_sent` int(11) NOT NULL,
`rows_examined` int(11) NOT NULL,
`db` varchar(512) NOT NULL,
`last_insert_id` int(11) NOT NULL,
`insert_id` int(11) NOT NULL,
`server_id` int(10) unsigned NOT NULL,
`sql_text` mediumtext NOT NULL
) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='Slow log';
我正在使用MySQL 5.7.18
I am using MySQL 5.7.18
$ mysql --version
mysql Ver 14.14 Distrib 5.7.18, for osx10.10 (x86_64) using EditLine wrapper
根据 MySQL 5.7文档,以下语法是
CREATE TABLE t1 (
ts TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
dt DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
);
上面的SQL语法有什么问题?
What is wrong with the SQL syntax above?
推荐答案
有趣的是,这两种方法都有效:
Interestingly, both these work:
`start_time` timestamp(6),
并且:
`start_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
您可以使用后者-将精度说明符放在定义之外.
You can use the latter -- leave the precision specifier out of the definition.
但是正确的方法是:
`start_time` timestamp(6) NOT NULL DEFAULT CURRENT_TIMESTAMP(6) ON UPDATE CURRENT_TIMESTAMP(6),
如文档中所述:>
如果
TIMESTAMP
或DATETIME
列定义包含显式小数秒精度值在任何地方,必须相同在整个列定义中使用.这是允许的:
If a
TIMESTAMP
orDATETIME
column definition includes an explicit fractional seconds precision value anywhere, the same value must be used throughout the column definition. This is permitted:
CREATE TABLE t1 (
ts TIMESTAMP(6) DEFAULT CURRENT_TIMESTAMP(6) ON UPDATE CURRENT_TIMESTAMP(6)
);
这是不允许的:
CREATE TABLE t1 (
ts TIMESTAMP(6) DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP(3)
);
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