GROUP BY 和 HAVING 子句。，，``sql，SELECT column_name, COUNT(*)，FROM table_name，GROUP BY column_name，HAVING COUNT(*) > 1;，``，，这段代码会返回在指定列中出现次数超过一次的所有记录。GROUP BY和HAVING子句。假设你有一个名为users的表，并且你想查找在email列中重复的数据，你可以使用以下查询：，，``sql，SELECT email, COUNT(*)，FROM users，GROUP BY email，HAVING COUNT(*) > 1;，`，，这个查询会返回所有在email`列中出现超过一次的记录及其出现的次数。Powered By Z-BlogPHP 1.7.3
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