oralce
//nvl(x,0) 如果查找到的x為null,就返回0
//sum() 配合group by 使用，將（）內的數據相加
//round() 將保留兩位小數，如果沒有兩位就不保留
//mecode(x, case1, value1, case2,value2,value3) 判斷：
SELECT oba03,
ROUND(SUM(NVL(msb05 * ecb21 *
DECODE(ecb13, '1', 1 / 3600, '2', 1 / 60, 1),
0)),
2) plantime,
ROUND(SUM(NVL(msb08 * ecb21 *
DECODE(ecb13, '1', 1 / 3600, '2', 1 / 60, 1),
0)),
2) outtime
FROM msb_file, ecb_file, oba_file
WHERE msb03 = ecb01
AND ecb02 = oba01
