選擇SQL中缺少表達式

Question

我是SQL和子查詢的新手，當我自己運行子查詢時，將獲得正確的數據輸出。 但是，當我運行完整查詢時，會收到錯誤消息

SELECT *第3行出現錯誤：ORA-00936：缺少表達式

這是我的代碼：

SELECT 
MAX(
    SELECT 
    SUM(
        ALLOCATION.HourlyRate 
        * 
        ACTION.HrsWorked
        ) 
    FROM ALLOCATION 
    INNER JOIN ACTION 
    ON ((ACTION.ActId  = ALLOCATION.ActId) AND (ACTION.EmpId  = ALLOCATION.EmpId)) 
    GROUP BY (ALLOCATION.ActId)
)
FROM ALLOCATION
GROUP BY (ALLOCATION.ActId)

解：

   SELECT MAX(sum_total_pay)
FROM
(
    SELECT SUM(ALLOCATION.HourlyRate *  ACTION.HrsWorked) AS sum_total_pay
    FROM ALLOCATION 
    INNER JOIN ACTION 
    ON ((ACTION.ActId  = ALLOCATION.ActId) AND (ACTION.EmpId  = ALLOCATION.EmpId))
    GROUP BY (ALLOCATION.ActId)
);

Answer 1

您還需要兩個括號：）

  SELECT MAX ( (  SELECT SUM (ALLOCATION.HourlyRate * ACTION.HrsWorked)
                    FROM ALLOCATION INNER JOIN ACTION ON (ACTION.ActId = ALLOCATION.ActId) AND (ACTION.EmpId = ALLOCATION.EmpId)
                GROUP BY (ALLOCATION.ActId)))
    FROM ALLOCATION
GROUP BY ALLOCATION.ActId

Select into MAX必須在括號內。

邏輯尚不清楚。 這樣就可以得出每次活動的總收入：

  SELECT ALLOCATION.ActId, SUM (ALLOCATION.HourlyRate * ACTION.HrsWorked) total_pay
    FROM ALLOCATION b INNER JOIN ACTION ON ACTION.ActId = ALLOCATION.ActId AND ACTION.EmpId = ALLOCATION.EmpId
GROUP BY ALLOCATION.ActId

如果您想查看哪個活動支付的費用最高，請通過desc訂購：

  SELECT *
    FROM (  SELECT ALLOCATION.ActId, SUM (ALLOCATION.HourlyRate * ACTION.HrsWorked) total_pay
              FROM ALLOCATION b INNER JOIN ACTION ON ACTION.ActId = ALLOCATION.ActId AND ACTION.EmpId = ALLOCATION.EmpId
          GROUP BY ALLOCATION.ActId)
ORDER BY total_pay DESC