Question

客户表共有1000个客户，其中2016年有1500个订单。但我们希望在2016财年显示所有客户的订单总数，无论客户是否在该风险中下订单。但SQL Server 2012中的以下查询仅显示1490.

我们在这里可能缺少什么？

SELECT c.CustomerID, count(*) AS TotalOrders
FROM Customers c
LEFT JOIN Orders o ON c.CustomerID = o.CustomerID
WHERE o.FiscalYear = '2016'
GROUP BY c.CustomerID

更新：

以下查询仅返回1条记录（1491） - 仍然缺少9条记录。

SELECT c.CustomerID, count(*) AS TotalOrders
FROM Customers c
LEFT JOIN Orders o ON c.CustomerID = o.CustomerID
                   AND o.FiscalYear = '2016'
GROUP BY c.CustomerID

Answer 1

您where子句正在将left outer join变为Inner join。

将其更改为AND：

SELECT c.CustomerID, count(o.CustomerID) AS TotalOrders
FROM Customers c
LEFT JOIN Orders o
    ON c.CustomerID = o.CustomerID
    AND o.FiscalYear = '2016'     -- Here
GROUP BY c.CustomerID

Answer 2

正确的SQL是：

SELECT c.CustomerID, count(o.CustomerID) AS TotalOrders,
       sum(count(o.CustomerID)) over () as TotalTotalOrders
FROM Customers c LEFT JOIN
     Orders o
     ON c.CustomerID = o.CustomerID AND o.FiscalYear = '2016'
GROUP BY c.CustomerID;

TotalTotalOrders应该是所有订单（或至少是有效客户ID的订单）。

Answer 3

这将列出所有客户，无论他们是否有任何订单，无论订单的年份如何。然后Sub SpitValues() Dim dvCell As Range Dim inputRange As Range Dim c As Range Dim i As Long 'Which cell has data validation Set dvCell = Worksheets("Sheet1").Range("G11") 'Determine where validation comes from Set inputRange = Evaluate(dvCell.Validation.Formula1) i = 1 'Begin our loop Application.ScreenUpdating = False For Each c In inputRange dvCell = c.Value Worksheets("SECURITIZATION").Cells(i, "A1").Value = Worksheets("SECURITIZATION").Range("G30").Value i = i + 1 Next c Application.ScreenUpdating = True将计算2016年下的所有订单，忽略其余订单，并返回一个整数（即它永远不会为空）。

sum

为什么这个LEFT OUTER JOIN不包括左边的所有主键

3 个答案: