MySQL查询-对一个相关表求和-对另一个相关表进行计数 [英] MySQL Query - Sum one related table - Count another related table
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问题描述
该Count与一个相关表配合良好,但是当我添加Sum时,该Count中的结果就显得过高了.
The Count works fine with one related table, but when I add the Sum I get overinflated results in the Count.
SELECT Orders.kp_OrderID AS `Order #`,
Orders.t_ServiceLevel AS `Service Level`,
Customers.t_CustCompany AS Company,
Orders.t_JobName AS `Job Name`,
Orders.t_JobStatus AS `Status`,
Orders.d_JobDue AS Due,
Orders.ti_JobDue AS Time,
COUNT(OrderItems.kf_OrderID) AS `Line Item`,
SUM(
`OrderItemComponents`.`n_QuantityPrintMaterial` * (
`OrderItemComponents`.`n_WidthInInches` * `OrderItemComponents`.`n_HeightInInches` / 144
)
) AS SqFt,
Orders.nb_JobFinished AS Finished
FROM Orders
INNER JOIN OrderItems ON Orders.kp_OrderID = OrderItems.kf_OrderID
INNER JOIN Customers ON Orders.kf_CustomerID = Customers.kp_CustomerID
INNER JOIN OrderItemComponents ON OrderItemComponents.kf_OrderID = Orders.kp_OrderID
WHERE Orders.d_JobDue > (
DATE_SUB(CURDATE(), INTERVAL 60 DAY)
)
GROUP BY Orders.kp_OrderID
ORDER BY `Line Item` DESC
推荐答案
将您的COUNT行切换为:
Switch your COUNT line to:
COUNT(DISTINCT OrderItems.kf_OrderID) AS `Line Item`
添加行时
INNER JOIN OrderItemComponents
ON OrderItemComponents.kf_OrderID = Orders.kp_OrderID
您返回了更多的行,因为我假设OrderItem可以包含多个组件.
you returned many more rows since an OrderItem can, I assume, contain multiple components.
更新
如果您有COUNT条语句,请尝试就地使用它:
Try using this in place if your COUNT statement:
(SELECT COUNT(OrderItems.kf_OrderID)
FROM OrderItems.kf_OrderID
WHERE OrderItems.kf_OrderID=Order.kf_OrderID) AS `Line Item`,
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