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mysql创造表时的空值和非空值设置有什么讲究

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Release： 2016-06-13 11:18:19
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mysql创建表时的空值和非空值设置有什么讲究?
mysql创建表时的空值和非空值设置有什么讲究?

mysql
------解决方案--------------------
我一般尽量不用null

如果你的0和null或者''和null有不同含义, 那么就需要允许空置
------解决方案--------------------
本帖最后由 xuzuning 于 2013-03-21 08:16:39 编辑 这要看你的业务需求了
空 NULL 表示什么都没有输入，也就是该数据项是无效的

如果你的业务需要数据项有初值，那么就应该用 NOT NULL（不为空）并设置初值
Related labels：
mysql nbsp null
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