如何解决子查询返回超过1个值的错误

Question

I'm trying to execute this stored procedure

ELSE IF(@Item_Type='Frames')
BEGIN
    SELECT 
       ID.Selling_Price, --0
       ID.Purchase_Price,--1
       @Discount AS Discount,--2

       IH.Item_Name AS Item_Group_Name,--3
       @Item_Group_Code AS Item_Group_Code,--4

       FD.Item_Code,        
       ID.Item_Name,
       FD.Material,     
       FD.Color,

       FD.RIM,
       FD.Frame_Code
    FROM 
       Frame_Details AS FD 
    LEFT JOIN 
       Item_Details AS ID ON FD.Item_Code = ID.Item_Code
    LEFT JOIN 
       Item_Header AS IH ON IH.Item_G_Code = ID.Item_G_Code             
    WHERE 
       FD.Status = '0' 
       AND FD.Item_Code = @Item_Code 
    GROUP BY  
       ID.Selling_Price, ID.Purchase_Price, IH.Item_Name, 
       FD.Item_Code, ID.Item_Name, FD.Material, FD.Color, FD.RIM, FD.Frame_Code
END

it will not execute successfully..this is the error message that I got

Subquery returned more than 1 value. This is not permitted when the subquery follows =, !=, <, <= , >, >= or when the subquery is used as an expression.

I have tried several examples given before, but they don't works for me.

Answer 1

It seems that the subquery returns more than one records. In this case, the result is a set, not a single value, while which is not allowed in your scenario. To avoid this issue, you may have a try to join the result of this subquery, or use TOP 1 or max or sum or AVG to return only one value.

Thanks