I WANT TO WRITE A update
i have input like

FIRST TIME RECORD COME
custkey customer_no Nomenclature_Code effdate endate
1 101 10050 06/27/2005 -

SECOND TIME RECORD COME

custkey customer_no Nomenclature_Code effdate endate
1 101 10050 06/27/2005 -
12 101 10052 06/28/2005


NOW I WANT TO UPDATE LIKE

custkey customer_no Nomenclature_Code effdate endate
1 101 10050 - ( 06/27/2005(effdate) - 1day(06/26/2005)
12 101 10052 06/28/2005 -


cUST_KEY IS a sequence key
plz advice
thnxs
Bobby



Create Table STG_Customertype2 (
CUST_KEY INTEGER,
Customer_No Varchar( 5 ),
Nomenclature_Code Varchar( 7 ),
ENDDATE DATE,
EFFDATE DATE );