mysql-MySQL：多字段复合统计
- WBOYOriginal
- 2016-06-06 09:35:50895browse
mysql
菜鸟求助：eves表中有三个国家字段，nat1, nat2, nat3，nat1为非空，其它两个不一定有数据。现在想统计3列中每个国家（包括出现在nat2和nat3里的国家）出现的次数，请问如何SELECT？感谢！！试过COUNT和GROUP BY，似乎无法实现啊……
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