Question

我有一个客户表和一个订单表，我试图检查以确保客户表中存在客户表中的客户，然后我才能执行其余的脚本。

这是造成问题的代码，

    alter proc Order
  @CustomerID int
  as
Declare @CusID int


select @CusID = dbo.CustomerTable.CustomerID
 from dbo.CustomerTable
inner join dbo.OrdersTable
on dbo.CustomerTable.CustomerID
= dbo.OrdersTable.CustomerID
 where dbo.OrdersTable.CustomerID = @CustomerID

if(@CusID != @CustomerID)
 begin
raiserror('The customer does not exist')
return 1
end

 exec Order 44

当我尝试使用不在表中的CustomerID执行脚本时，它不会给我错误消息。任何帮助将不胜感激。

Answer 1

ALTER PROCEDURE dbo.[Order]  --<-- Avoid using key words for object names
@CustomerID int
AS
BEGIN
  SET NOCOUNT ON;
IF NOT EXISTS
            (select 1
            from dbo.CustomerTable inner join dbo.OrdersTable
            on dbo.CustomerTable.CustomerID = dbo.OrdersTable.CustomerID
            where dbo.OrdersTable.CustomerID = @CustomerID)
 BEGIN
   RAISERROR('The customer does not exist', 16,1)
   RETURN 1
 END
    RETURN @CustomerID;
END

EXECUTE PROC

由于此过程返回一个值，您需要执行一些不同的操作，例如

DECLARE @RtnValue INT;

EXECUTE @RtnValue =  dbo.[Order] 44

SELECT @RtnValue;    --<-- now you can use this value whatever you want to do with it

Answer 2

IF @CusID IS NULL
    BEGIN    
    raiserror('The customer does not exist', 0, 1)
    RETURN 1
    END

检查另一个表中是否存在id

2 个答案: