Question

我有一张桌子OrderSpecs。我需要通过OrderSpecs选择customer ID中的所有行，但只需按order ID选择每个订单的最后一次出现（按时间戳）。我还希望我的查询计算它为每个OrderID找到的出现次数。

这是我的表格（浓缩以仅显示关键信息）：

OrderSpecs

ID       OrderID    CustomerID        CreatedDate                 SpecDocument
1        1           5                 01/08/2012 11:00:00         *Amendment1*
2        1           5                 02/08/2012 15:32:41         *Amendment2*
3        2           31                04/08/2012 16:19:00         *Amendment1*
4        3           5                 05/08/2012 12:10:12         *Amendment1*
5        4           10                08/08/2012 09:32:56         *Amendment1*
6        1           5                 09/08/2012 11:47:02         *Amendment3*

按日期和CustomerID选择最近的订单行时，我的查询工作正常：

SELECT 
    ID, CustomerID, EstimateNo, OrderYear, OrderNo, ProductionNo, AddedBy,    
    AddedDate, SizeLength, SizeWidth, HomeModelID, HomeTypeID, DrawingNo, 
    CustomerReference, BuildPieces, ProductionPieces, Notes, SpecDocument, OrderID
FROM  
    OrderSpecs AS o
WHERE 
    (AddedDate = (SELECT MAX(AddedDate) AS Expr1
                  FROM OrderSpecs AS i
                  WHERE (o.OrderID = OrderID))) 
    AND (CustomerID = @CustomerID)

但是，我无法确定如何计算每个OrderID的遮挡数量。

例如，我希望我的输出表格像这样（按CustomerID = 5搜索）：

ID     OrderID     CustomerID     CreatedDate            SpecDocument      Count
6      1           5              09/08/2012 11:47:02    *Amendment3*      3
4      3           5              05/08/2012 12:10:12    *Amendment1*      1

Answer 1

应该使用SELECT（未经测试）

中的子查询

SELECT 
    ID, CustomerID, EstimateNo, OrderYear, OrderNo, ProductionNo, AddedBy,    
    AddedDate, SizeLength, SizeWidth, HomeModelID, HomeTypeID, DrawingNo, 
    CustomerReference, BuildPieces, ProductionPieces, Notes, SpecDocument, OrderID,
    (SELECT COUNT(*) FROM OrderSpecs AS os WHERE o.OrderID=os.OrderID) as [Count]
FROM  
    OrderSpecs AS o
WHERE 
    (AddedDate = (SELECT MAX(AddedDate) AS Expr1
                  FROM OrderSpecs AS i
                  WHERE (o.OrderID = OrderID))) 
    AND (CustomerID = @CustomerID)

SQL选择最后一次出现的行＆amp;计算出现次数

1 个答案: