SELECT D.DEPT_CODE, DEPT_NAME, ORDER_NO, C.CUST_CODE, CUST_NAME, ORDER_AMT
FROM TBL_ORDERS AS O
INNER JOIN TBL_DEPT AS D
ON O.DEPT_CODE = D.DEPT_CODE
LEFT OUTER JOIN TBL_CUST AS C
ON O.CUST_CODE = C.CUST_CODE;