Question

以下是我参加的数据库课程。它是SQL Server上的存储过程。目的是防止不良数据进入数据库。由于某种原因，下面的三个if语句，引发和错误，但仍然将数据放入数据库。我无法弄清楚为什么。这不再适用于班级，而是因为我自己的个人知识，因为作业已经评级。

那么，为什么IsNumeric（@CC）= 0和Len（@CC）＆lt; 12仍然允许数据进入数据库，即使错误被提出（我相信@cc null检查也允许坏数据）。提前谢谢。

USE [CIS6**]
GO
/****** Object:  StoredProcedure [dbo].[sp_insertCC]    Script Date: 5/20/2014 1:14:05 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author:      <Author,,Name>
-- Create date: <Create Date,,>
-- Description: <Description,,>
-- =============================================
ALTER PROCEDURE [dbo].[sp_insertCC] 
    -- Add the parameters for the stored procedure here
    @clientID int, @CC varchar(16), @expDate varchar(10), @lastFour varchar(4)
AS

If @clientID is Null or @clientID=''
    Begin
        RAISERROR('clientId cannot be null or empty', 16, 20)
    End
Else
    If ISNUmeric(@clientID)=0
        Begin
            RAISERROR('clientID must be a number', 16, 21)
        End
    Else
            If Not Exists (Select ClientID from CreditCard Where ClientID=@clientID)
                Begin
                    RAISERROR('clientId is not in the records.', 16, 22)
                End
            Else
                If @CC is Null or @CC=''
                    Begin
                        Raiserror('Credit Card number must have a value.', 16, 30)
                    End
                Else
                    If ISNUMERIC(@CC)=0
                        Begin
                            Raiserror('Credit Card number must be a number.', 16, 31)
                        End
                    Else
                        If LEN(@CC) < 12 
                            Begin
                                RAISERROR('Credit Card Number length too short.', 16, 32)
                            End
                        Else
                            If LEN(@CC) > 19 
                                Begin
                                    RAISERROR('Credit Card Number length too long.', 16, 33)
                                End
                            Else
                                If @expDate='' or @expDate is Null
                                    Begin
                                        Raiserror('Date must have a value.', 16, 40)
                                    End
                                Else
                                    If ISDATE(@expDate)=0
                                        Begin
                                            Raiserror('Please input a correct date value.', 16, 43)
                                        end
                                    Else            
                                        Declare @checkDate date, @todaysdate date;
                                        set @todaysdate=getdate();
                                        set @checkDate= Convert(date, @expDate, 101)
                                        If @checkDate < @todaysdate
                                            Begin
                                                Raiserror('Date in the past.', 16, 41)
                                            End
                                        Else


                                            BEGIN

                                                OPEN SYMMETRIC KEY CreditCardKey DECRYPTION BY certificate CreditCardCert;

                                                INSERT INTO CreditCard VALUES (CIS6**.dbo.HashCC(@CC),
                                                    EncryptByKey(Key_GUID('CreditCardKey'), @CC),
                                                    @CC, @lastFour, 1, @expDate, @clientID);
                                                IF @@ERROR <> 0 
                                                BEGIN
                                                    CLOSE SYMMETRIC KEY CreditCardKey;
                                                    RETURN(1)
                                                 END
                                                ELSE
                                                 BEGIN
                                                    CLOSE SYMMETRIC KEY CreditCardKey;
                                                    RETURN(0)
                                                 END

            END

Answer 1

我的意思是您需要在代码中添加BEGIN ... END，如下所示：

Else 
    BEGIN --<-- THIS ONE
        Declare @checkDate date, @todaysdate date;
        set @todaysdate=getdate();
        set @checkDate= Convert(date, @expDate, 101)
        If @checkDate < @todaysdate
            Begin
                Raiserror('Date in the past.', 16, 41)
            End
        Else
            BEGIN

                OPEN SYMMETRIC KEY CreditCardKey DECRYPTION BY certificate CreditCardCert;

                INSERT INTO CreditCard VALUES (CIS6**.dbo.HashCC(@CC),
                    EncryptByKey(Key_GUID('CreditCardKey'), @CC),
                    @CC, @lastFour, 1, @expDate, @clientID);
                IF @@ERROR <> 0 
                BEGIN
                    CLOSE SYMMETRIC KEY CreditCardKey;
                    RETURN(1)
                 END
                ELSE
                 BEGIN
                    CLOSE SYMMETRIC KEY CreditCardKey;
                    RETURN(0)
                 END

            END

    END --<-- THIS ONE

如果您的IF ... ELSE Block Sql语句只有1个Sql查询，则不需要包含BEGIN ... END。如果你的IF ... ELSE Block Sql语句有超过1个Sql查询，你需要包含BEGIN ... END让它在你的Sql查询块中执行所有的Sql Query。（从这里http://sqltutorials.blogspot.com/2007/06/sql-ifelse-statement.html）

为什么if语句不会阻止坏数据，但仍然会引发错误

1 个答案: