3

我需要为具有重复项的多部分标识符选择某些字段。

我有查询以正确获取重复项。

SELECT   b.MemEmpID, b.LastName, b.FirstName
               FROM     table1 As b
               GROUP BY b.MemEmpID, b.LastName, b.FirstName
               HAVING   Count(*) > 1

但是在找到重复项后，我需要从同一个表中获取更多信息，但仅限于具有重复项的多部分标识符。所以像下面这样。

有人可以帮我正确的语法吗？

SELECT a.memempid, a.depkey, a.lastname, a.firstname, a.birthdate, a.memrelation
FROM   table1 As a
INNER JOIN(SELECT   b.MemEmpID, b.LastName, b.FirstName
               FROM     table1 As b
               GROUP BY b.MemEmpID, b.LastName, b.FirstName
               HAVING   Count(*) > 1)
ON b.memempid = a.memempid
AND b.lastname = a.lastname
AND b.firstname = a.firstname
4

1 回答 1

2

你真的很亲近。您需要为子查询设置别名。

table1 As b通过分组失去了它的范围，()因此您需要为带括号的子查询设置别名。您可以重用b- 它只会知道返回的列，但为了清楚起见，我选择(...) as c消除歧义。

SELECT a.memempid, a.depkey, a.lastname, a.firstname, a.birthdate, a.memrelation
FROM   table1 As a
INNER JOIN
    (SELECT   b.MemEmpID, b.LastName, b.FirstName
     FROM     table1 As b
     GROUP BY b.MemEmpID, b.LastName, b.FirstName
     HAVING   Count(*) > 1
    ) as c
ON c.memempid = a.memempid
    AND c.lastname = a.lastname
    AND c.firstname = a.firstname
于 2013-03-05T14:43:33.580 回答