摘要：select aa,a from a group by aa ,a having count(*)>1顺便摘录一点关于 having 的说明 使用 HAVING 子句选择行 HAVING 子句对 GROUP BY 子句设置条件的方式与 WHERE 子句和 SELECT 语句交互的方式类似。WHERE 子句搜索条件在进行分组操作之前应用；而 HAVING 搜索条件在进行...
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posted @ 2007-04-03 09:28
