Possible Duplicate:
How do you set a default value for a MySQL Datetime column?可能重复:如何为MySQL Datetime列设置默认值?
I have a table with column CreatedDate of data type datetime and i want to be able to set its default value to current DateTime how do i do it?
我有一个数据类型为datetime的列CreatedDate的表,我希望能够将其默认值设置为当前DateTime我该怎么做?
I tried Now() and CurrentTimestamp but no luck so far!!!
我试过Now()和CurrentTimestamp但到目前为止没有运气!
2 个解决方案
#1
5
You can only set a static default in the table definition.
So unless you want to call ALTER TABLE every minute....
您只能在表定义中设置静态默认值。所以,除非你想每分钟调用ALTER TABLE ....
Use a trigger:
使用触发器:
DELIMITER $$
CREATE TRIGGER bu_table1_each BEFORE UPDATE ON table1 FOR EACH ROW
BEGIN
SET new.datefield = NOW();
END $$
DELIMITER ;
#2
1
I do not think you can do it with DateTime.
我不认为你可以用DateTime做到这一点。
See: How do you set a default value for a MySQL Datetime column?
请参阅:如何为MySQL Datetime列设置默认值?
#1
5
You can only set a static default in the table definition.
So unless you want to call ALTER TABLE every minute....
您只能在表定义中设置静态默认值。所以,除非你想每分钟调用ALTER TABLE ....
Use a trigger:
使用触发器:
DELIMITER $$
CREATE TRIGGER bu_table1_each BEFORE UPDATE ON table1 FOR EACH ROW
BEGIN
SET new.datefield = NOW();
END $$
DELIMITER ;
#2
1
I do not think you can do it with DateTime.
我不认为你可以用DateTime做到这一点。
See: How do you set a default value for a MySQL Datetime column?
请参阅:如何为MySQL Datetime列设置默认值?