如何在SQL表中找到重复记录

Question

我有一张表有近20000条
列的记录

Id      SubjectId      UniqueId
1        54            1
1        58            2
1        59            3
1        60            4
2        54            5
2        58            6
2        59            7
2        60            8
2        60            9
3        54            10
3        70            11

我想选择那些重复
像
结果一样的记录

Id      SubjectId      UniqueId
 2        60            8
 2        60            9
 7        54            15
 7        54            18
 7        54            30

帮帮我怎么能这样做

Answer 1

使用 EXISTS()

SELECT  a.*
FROM    tableName a
WHERE   EXISTS
        (
            SELECT  1
            FROM    tableName b
            WHERE   a.ID = b.ID AND
                    a.SubjectID = b.subjectID
            GROUP   BY Id, SubjectId
            HAVING  COUNT(*) > 1
        )

• SQLFiddle演示