Question

我有2个表由StudentID和ParkingID加入。我的表B有重复的停车信息。我希望获得StudentID，StudentName，ParkingSpace编号和重复数。这是我的第一篇文章，请原谅我，如果我不遵守所有正确的协议。我很感激帮助。

示例：

Table A:

StudentID     StudentName
----          ------
001           Mary
002           Jane
003           Peter
004           Smith
005           Kathy

Table B:

ParkingID     ParkingSpace
-----         -----
001           25
001           25
002           18
003           74
004           22
005           31
005           31
005           31
005           31
005           31

这是我的目标。

StudentID     StudentName  ParkingSpace  dupCount
----          ------       ------        ------
001           Mary         25            2
005           Kathy        31            5

Answer 1

测试数据

DECLARE @Table_1 TABLE (StudentID VARCHAR(100),StudentName VARCHAR(100))
INSERT INTO @Table_1 VALUES 
('001','Mary'),('002','Jane'),('003','Peter'),
('004','Smith'),('005','Kathy')

DECLARE @Table_2 TABLE 
(ParkingID VARCHAR(100),ParkingSpace INT)
INSERT INTO @Table_2 VALUES
('001',25),('001',25),('002',18),('003',74),('004',22),('005',31),
('005',31),('005',31),('005',31),('005',31)

<强>查询

SELECT T1.StudentID
      ,T1.StudentName
      ,T2.ParkingSpace
      ,COUNT(T2.ParkingSpace) AS Duplicates

FROM @Table_1 T1 INNER JOIN @Table_2 T2
ON T1.StudentID = T2.ParkingID
GROUP BY  T1.StudentID
         ,T1.StudentName
         ,T2.ParkingSpace
HAVING COUNT(T2.ParkingSpace) > 1

结果集

╔═══════════╦═════════════╦══════════════╦════════════╗
║ StudentID ║ StudentName ║ ParkingSpace ║ Duplicates ║
╠═══════════╬═════════════╬══════════════╬════════════╣
║       001 ║ Mary        ║           25 ║          2 ║
║       005 ║ Kathy       ║           31 ║          5 ║
╚═══════════╩═════════════╩══════════════╩════════════╝

Answer 2

select a.studentId, a.studentName, 
b.parkingspace, count(1) as dupcount
from a
join b on a.studentId = b.parkingid
group by a.studentId, a.studentName, b.parkingspace
having dupcount > 1

Answer 3

SELECT
  A.studentID,
  A.studentName,
  B.parkingSpace,
  COUNT(B.parkingSpace)
FROM A

JOIN B ON A.StudentID = B.ParkingID

GROUP BY
A.studentID,
  A.studentName,
  B.parkingSpace

Answer 4

这是您的问题的解决方案。

select studentid, studentname, parkingspace , count(*) dupcount
from tablea inner join tableb on tablea.studentid=tableb.parkingid
group by studentid, studentname, parkingspace having count(*)>1

我们计算重复项，并having count(*)>1仅显示真正的重复项。

http://sqlfiddle.com/#!2/29c2d/2

SQL Query连接第二个表有重复的表

4 个答案: