Try this
SELECT T3.EmpId,T3.PayId,Table2.PayAmount,T3.PaidAmount FROM
(SELECT EmpId,PayId,SUM(PaidAmount) AS PaidAmount
FROM Table3
GROUP BY EmpId, PayID) AS T3
INNER JOIN Table2
ON Table2.PayId=T3.PayId
Output
EmpId PayId PayAmount PaidAmount
----------- ----------- ----------- -----------
1 1 1000 600
2 1 1000 1000
1 2 2000 1000
2 2 2000 2000
Check your sample output, it seems not correct.
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Well, With regarding your comments, I assumed each employee join with each PayID. Therefore we have to use
CROSS JOIN
for that
SELECT Table1.EmpId,Table1.EmpName,Table2.PayId,Table2.PayAmount,ISNULL(PaidAmount,0)AS PaidAmount
FROM Table1
CROSS JOIN Table2
LEFT OUTER JOIN
(SELECT EmpId,PayId,SUM(PaidAmount) AS PaidAmount
FROM Table3
GROUP BY EmpId, PayID) AS T3
ON T3.PayId =Table2.PayId AND T3.EmpId = Table1.EmpId
WHERE Table2.PayId=1
you will get hte following output
EmpId EmpName PayId PayAmount PaidAmount
----------- ------- ----------- ----------- -----------
1 A 1 1000 600
2 B 1 1000 1000
3 C 1 1000 0
Please check your sample output, pay amount of EmpId 2 is not correct. It should be 1000 if you pass PayID=1