What is the use of MERGE statement in SQL? How and where all is it used?

Hi Nethra,

Using Merge , we can Insert/Update records in our database table, without explicitly checking for the existence of records to perform operations like Insert or Update. in single statement

for e.g

    MERGE INTO dbo.tbl_Customers AS C
         USING dbo.tbl_CustomersTemp AS CT
                 ON C.CustID = CT.CustID
    WHEN MATCHED THEN
      UPDATE SET
        C.CompanyName = CT.CompanyName,
        C.Phone = CT.Phone
    WHEN NOT MATCHED THEN
       INSERT (CustID, CompanyName, Phone)
       VALUES (CT.CustID, CT.CompanyName, CT.Phone)

see here you dont need to check sepratly whether perticular record is alreadty their......you do it in single statment.

Thanks,
Pravin.

2 Replies

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Suthish Nair15y ago
Accepted answer
Every thing about MERGE: http://technet.microsoft.com/en-us/library/bb510625.aspx
0
Pravin More15y ago
Hi Nethra,
             Using Merge , we can Insert/Update records in our database table, without explicitly checking for the existence of records to perform operations like Insert or Update. in single statement
for e.g
    MERGE INTO dbo.tbl_Customers AS C
         USING dbo.tbl_CustomersTemp AS CT
                 ON C.CustID = CT.CustID
    WHEN MATCHED THEN
      UPDATE SET
        C.CompanyName = CT.CompanyName,
        C.Phone = CT.Phone
    WHEN NOT MATCHED THEN
       INSERT (CustID, CompanyName, Phone)
       VALUES (CT.CustID, CT.CompanyName, CT.Phone)
see here you dont need to check sepratly whether perticular record is alreadty their......you do it in single statment.
Thanks,
Pravin.
0