Find and replace value between two tables column with different datatype

Question

I have tow tables in sql server 2008

TBL_CustomerMaster
[FilingId] [numeric]  (18, 0) NOT NULL,
[CustId]   [nvarchar] (500)   COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,

TBL_Customer
[FilingId]  [numeric]  (18, 0) NOT NULL,
[CustUnqId] [numeric]  (18, 0) NOT NULL,
[CustId]    [nvarchar] (500)   COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL,

I used bulk insert to load data into two tables for each FilingId, CustId's for two tables are same. I have generated unique CustUnqId for TBL_Customer

Now i want to map the CustUnqId with CustId of TBL_CustomerMaster ie replace CustId in TBL_CustomerMaster with corresponding CustUnqId form TBL_Customer

kindly suggest the solution.

Answer 1

You can try this, but enclose this into transaction and do the testing before putting anything into production environment:

SELECT  a.CustId,
        b.CustUnqId
INTO    #temp
FROM    TBL_CustomerMaster a
JOIN    TBL_Customer b ON
        a.CustId = b.CustId

UPDATE  TBL_CustomerMaster
SET     CustId = t.CustUnqId
FROM    TBL_CustomerMaster a
JOIN    #temp t ON
        t.CustId = a.CustId