Question : sql statement needed

need a sql statement to show that for each time a car is added to (product table)...inventory is reduced from (part table).


Table name: PRODUCT                         
PROD_CODE      PROD_QOH            
car      24            
                  
                        
Table name: PART
PART_CODE      PART_QOH
Frame      22
Moulding      23

Answer : sql statement needed

begin tran

insert into PRODUCT select ...
if @@ROWCOUNT > 0
  UPDATE  Part
  SET qty = qty -1
  WHERE PART_QOH = ???
IF @@Error <> 0
BEGIN
   ROLLBACK TRAN
   return

END
commit tran