How to Update a Target Table by Mapping with another Table in SQL Server

SQL Query to Update a Target Table by Mapping with another Table in SQL Server

Suppose , we have a Target Table called 'Tbl_Customers', in which the columns [Cust_Segment] and [Bookings_Flag] are need to update by Mapping it with a another Table called 'Map_Table' . we can do it by using the Update query as follows..

With Inner Join :

UPDATE [Tbl_Customers]
SET [Cust_Segment] = M.[CustSegment],
[Bookings_Flag]= CASE When M.[Bookings_Type]='Product' Then 'Prod' ELSE 'Svc' END
From [Tbl_Customers] C Inner Join [Map_Table] M
On C.Cust_Id=M.CustId

With Where Clause :

UPDATE [Tbl_Customers]
SET [Cust_Segment] = M.[CustSegment],
[Bookings_Flag]= CASE When M.[Bookings_Type]='Product' Then 'Prod' ELSE 'Svc' END
From [Tbl_Customers] C, [Map_Table] M
Where C.Cust_Id=M.CustId

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