SELECT td.DEPT_CODE, td.DEPT_NAME, ORDER_NO, tc.CUST_CODE, tc.CUST_NAME, ORDER_AMT
FROM TBL_ORDERS AS main
INNER JOIN TBL_DEPT AS td ON main.DEPT_CODE = td.DEPT_CODE
LEFT OUTER JOIN TBL_CUST AS tc ON main.CUST_CODE = tc.CUST_CODE
ORDER BY main.DEPT_CODE, ORDER_NO;