Sql UPDATE语句的问题

我想给实验室里最赚钱的员工加薪9%

我写这个查询是为了找到最赚钱的员工：

SELECT *
FROM (
SELECT SALESPERSONS.EmpID
  , SALESPERSONS.Ename
  , ((SUM(NVL(ORDERITEMS.Qty, 0) * NVL(INVENTORY.Price, 0)) - NVL(SALESPERSONS.Salary, 0))) AS Profit
FROM SALESPERSONS, ORDERS, ORDERITEMS, INVENTORY
WHERE SALESPERSONS.EmpID = ORDERS.EmpID (+)
AND ORDERS.OrderID = ORDERITEMS.OrderID (+)
AND ORDERITEMS.PartID = INVENTORY.PartID (+)
GROUP BY SALESPERSONS.EmpID
  , SALESPERSONS.Ename
  , SALESPERSONS.Salary
ORDER BY Profit DESC)
WHERE rownum = 1)

我已经验证了这是可行的，因为它不是一个很大的数据库，所以我可以手动执行此操作

然后，我创建了一个更新声明，为这名员工加薪：

UPDATE SALESPERSONS
SET Salary = (
SELECT MAX(SALARY)+MAX(SALARY)*.09
FROM SALESPERSONS, (SELECT *
FROM (
SELECT SALESPERSONS.EmpID
  , SALESPERSONS.Ename
  , ((SUM(NVL(ORDERITEMS.Qty, 0) * NVL(INVENTORY.Price, 0)) - NVL(SALESPERSONS.Salary, 0))) AS Profit
FROM SALESPERSONS, ORDERS, ORDERITEMS, INVENTORY
WHERE SALESPERSONS.EmpID = ORDERS.EmpID (+)
AND ORDERS.OrderID = ORDERITEMS.OrderID (+)
AND ORDERITEMS.PartID = INVENTORY.PartID (+)
GROUP BY SALESPERSONS.EmpID
  , SALESPERSONS.Ename
  , SALESPERSONS.Salary
ORDER BY Profit DESC)
WHERE rownum = 1));

这将更新所有11名员工的工资

---

我在想我到底做错了什么。我的top查询只返回一个结果

下面的修改应该有效

UPDATE SALESPERSONS
    SET Salary = (
    SELECT MAX(SALARY)+MAX(SALARY)*.09
    FROM SALESPERSONS WHERE
    EmpID in 
     (SELECT EmpID
    FROM (
    SELECT SALESPERSONS.EmpID
      , SALESPERSONS.Ename
      , ((SUM(NVL(ORDERITEMS.Qty, 0) * NVL(INVENTORY.Price, 0)) - NVL(SALESPERSONS.Salary, 0))) AS Profit
    FROM SALESPERSONS, ORDERS, ORDERITEMS, INVENTORY
    WHERE SALESPERSONS.EmpID = ORDERS.EmpID (+)
    AND ORDERS.OrderID = ORDERITEMS.OrderID (+)
    AND ORDERITEMS.PartID = INVENTORY.PartID (+)
    GROUP BY SALESPERSONS.EmpID
      , SALESPERSONS.Ename
      , SALESPERSONS.Salary
    ORDER BY Profit DESC)
    WHERE rownum = 1));

我更喜欢sql server，但我认为您的更新没有WHERE，因此它会更新表中的每一行，并使用内部查询获取每一行的薪资。您必须在外部级别有一个WHERE，用于指示要更新的行

如果这是一个一次性查询，您只需获取相关员工的PK，并在WHERE中使用

也许是这样的：

UPDATE SALESPERSONS
SET Salary = Salary+Salary*.09
WHERE EmpId=(
  SELECT TOP 1 SALESPERSONS.EmpID
FROM SALESPERSONS, ORDERS, ORDERITEMS, INVENTORY
WHERE SALESPERSONS.EmpID = ORDERS.EmpID
AND ORDERS.OrderID = ORDERITEMS.OrderID
AND ORDERITEMS.PartID = INVENTORY.PartID
GROUP BY SALESPERSONS.EmpID
  , SALESPERSONS.Ename
  , SALESPERSONS.Salary
ORDER BY Profit DESC);

---

从销售人员中选择*。。。创建笛卡尔积。我想知道这一点，但这一点：从销售人员，选择销售人员。从。。。返回了相同的结果。我知道你说这是一个小数据库，但我想知道这个更新查询的性能和可读性。有趣的是，在ID上引用多个表并使用WHERE implicit JOIN子句而不是JOIN explicit JOIN语句。看这个。