SQL存储过程基础语法问题，不知道用啥符号~
CREATE   PROCEDURE   [月统计]
(
@Year   [nvarchar](4),
@Month   [nvarchar](2),
@ClassID   [int]
)
AS

SELECT   SUM(dbo.Order_Product.OP_Price   *   dbo.Order_Product.OP_ProductNumber)  
FROM   dbo.Product_Class   INNER   JOIN
            dbo.Product_List   ON  
            dbo.Product_Class.PC_ID   =   dbo.Product_List.PL_ClassID   INNER   JOIN
            dbo.Order_Product   ON  
            dbo.Product_List.PL_ID   =   dbo.Order_Product.OP_ProductID
WHERE   ( ', '   +   dbo.Product_Class.PC_ParentIDs   +   ', '   LIKE   '%@ClassID% ')   AND  
            (LEFT(dbo.Order_Product.OP_OrderID,   4)   =   @Year)   AND   (CONVERT(int,  
            SUBSTRING(dbo.Order_Product.OP_OrderID,   5,   2))   =   @Month)
GO


就是
( ', '   +   dbo.Product_Class.PC_ParentIDs   +   ', '   LIKE   '%,@ClassID,% ')
这个参数~本来应该是这样的~
( ', '   +   dbo.Product_Class.PC_ParentIDs   +   ', '   LIKE   '%,111,% ')
可是我不知道怎么连……这样子是不行的吧？取出来是空值~

------解决方案--------------------
LIKE '% '+@ClassID+ '% '
------解决方案--------------------
LIKE '% ' + @ClassID + '% '
------解决方案--------------------
SELECT SUM(dbo.Order_Product.OP_Price * dbo.Order_Product.OP_ProductNumber)
FROM dbo.Product_Class INNER JOIN
dbo.Product_List ON
dbo.Product_Class.PC_ID = dbo.Product_List.PL_ClassID INNER JOIN
dbo.Order_Product ON
dbo.Product_List.PL_ID = dbo.Order_Product.OP_ProductID
WHERE (dbo.Product_Class.PC_ParentIDs LIKE '% ' + @ClassID + '% ') AND
(LEFT(dbo.Order_Product.OP_OrderID, 4) = @Year) AND (CONVERT(int,
SUBSTRING(dbo.Order_Product.OP_OrderID, 5, 2)) = @Month)