MySQL-如何修改列的默认值? [英] MySQL - How to modify column default value?
问题描述
如何将列的默认值从无"更改为其他值?例如,如果我在创建该行时未指定日期,则希望我的日期的默认值是0000-00-00.
How do I change my column's default value from None to something else? For example, I want my dates to have a default value of 0000-00-00 if I don't specify one when I create the row.
我在phpMyAdmin中理解了这一点,但是我不确定如何通过命令提示符来做到这一点.
I understand this in phpMyAdmin, but I'm not sure how to do it via command prompt.
我也了解添加列时的操作方法.但是我所有的列都是经过制作的,并且其中一些包含数据.
I also understand how to do this when adding a column. But all of my columns are made and have data in some of them.
ALTER TABLE table1 ADD COLUMN foo INT DEFAULT 0;
通过搜索,我找到了这一行,但是我不确定这是否是我想要的吗?
From searching, I found this line, but I'm not sure if that's what I want?
ALTER TABLE foobar_data MODIFY COLUMN col VARCHAR(255) NOT NULL DEFAULT '{}';
推荐答案
使用 ALTER TABLE 来更改或修改 默认列的值.检查此链接 ALTER TABLE SYNTAX (更改表语法)
Use ALTER TABLE to CHANGE or MODIFY the DEFAULT value of column. Check this link ALTER TABLE SYNTAX
ALTER TABLE `tableName` CHANGE `columnName` `columnName` DATE DEFAULT '0000-00-00';
ALTER TABLE `tableName` MODIFY `columnName` DATE DEFAULT '0000-00-00';
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