SQL选择最后一次出现的行和计数出现次数

Question

I have a table OrderSpecs . I need to select all of the rows from OrderSpecs by a customer ID , but only selecting the last occurrence (by a time stamp) of each order by an order ID . I would also like my query to count the number of occurrences it found for each OrderID .

Here is my table (condensed to show only the key information):

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*

My query works fine when selecting the most recent order rows by date and CustomerID :

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)

However, I am unable to work out how to count the number of a occourances there are for each OrderID .

For example, I would like my output table to be like this (searching by CustomerID = 5 ):

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

Should work with a sub-query in the SELECT (untested)

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)