Sql query to Load only new records,or update old records

Question

Hi,
I need a query (not stored procedure) to insert only new records otherwise update existing records.
I tried by creating "Merge statement in SQl", but the sql query is wrong,it is not updating,always inserting records(replicating..1,2,4,8,16,32..).
below is my sample query,
Here "FACT_mytbl -FCT" is my fact table.(which need to update if already records found ,otherwise insert as new records).
*Inside select ---the table   E_tbl1,E_tbl2  is the business logic table ,using this two table only ,"FACT_mytbl" was created  .So the "S" alias will be the source
table and "FCT" will be target table. based on this we have to insert or update records.   
  ---Query starts-------------------------------------                    
 MERGE INTO [FACT_mytbl]  FCT
 USING  (
       SELECT 
       FCT1.ID
      ,FCT1.PKcol1
      ,FCT1.FKcol1
      ,FCT1.col1
      ,FCT1.col2
     , FCT1.col3     
   FROM  [FACT_mytbl] FCT1 WITH(NOLOCK)        
   LEFT JOIN dbo.E_tbl1 CT WITH(NOLOCK)
ON CT.PKcol1=FCT1.PKcol1
   LEFT JOIN dbo.E_tbl2 CT1 WITH(NOLOCK)
ON CT1.PKcol1=FCT1.PKcol1
   ) S  
   ON FCT.PKcol1 = S.PKcol1 
 WHEN MATCHED AND (FCT.PKcol1 ! = S.PKcol1 ) THEN
 UPDATE SET       
       FCT.col1
      ,FCT.col2
      ,FCT.col3     
 WHEN NOT MATCHED THEN 
 INSERT VALUES
       S.ID
      ,S.PKcol1
      ,S.FKcol1
      ,S.col1
      ,S.col2
     , S.col3     
--query ends----------------
any suggestions,
Thanks,
R.B

Answer 1

Hi Bhupesh_Rajasekaran,
According to your description, if you want to insert only new records which does not exist in destination and update existing records which does exist in destination. We usually accomplish these in two statement.
1.A join statement to update records.
2.A insert statement for new records.
Also we can use MERGE in SQL Server to insert, update at the same time. You specify a "Source" record set and a "Target" table, and the join between the two. You then specify the type of data modification that is to occur when the records between the two
data are matched or are not matched. For more information, there is an similar example about merge in SQL Server, you can review the following article.
http://www.codeproject.com/Tips/590085/Merge-in-SQL-Server
Regards,
Sofiya Li
Sofiya Li
TechNet Community Support