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mysql 联合主键？

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Release： 2016-06-23 14:16:54
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本帖最后由 u010572351 于 2013-07-24 18:56:42 编辑

第一次听说这个东西，将多列联合起来形成一个主键，为的是行记录整体上不重复，这个不就是2NF的内容吗？

回复讨论(解决方案)

几范式我也忘记了

但是这么做应该可以降低数据库的冗余

当年数据库原理学的也是一头雾水啊...范式定义也忘了

大些的系统经常这么做，使用业务逻辑上的唯一性，而不是数据库系统上的唯一性。
这样更有利于约束业务逻辑，不产生冗余。

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