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数据select count时多个字段确定唯一的问题_MySQL

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2016-06-01 13:30:461549browse

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数据select count时多个字段确定唯一的问题

 

MySQL中语句：

 

select count(distinct table1.id, table2.type)...//省略

 

 

SQL Server中不能那样用，可以使用拼接：

 

select count(distinct str(table1.id)+'-'+str(table2.type))....//后面省略

 

如果使用Hibernate等框架就另当别论了

 

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