sql - 如果不可用，如何设置列值

Question

我有一张如下表。表名：TESTNUMBERS

ID(INT)   NUMBER(INT)    NAME(NVARCHAR(50))
1         1             Test
2         1             Test
3         2             Test2

当我插入 NUMBER 列时，如果不可用，我需要增加，如果可用，则最大 id 值 + 1 并确保该数字是否已作为参数传递，然后将其保存为原样。（这是为了确保行与NAME 也将具有相同的 NUMBER 列）。

我写了一个 SP，但有一些语法问题。

CREATE PROCEDURE TEST_STOREDPROC
@Name           NVARCHAR(50),
@Number         INT = 0,
@ID INT      
AS
BEGIN
  SET NOCOUNT ON
BEGIN TRY
        DECLARE @IncrementID SMALLINT; SET @IncrementID=1;   
        DECLARE @IncrementNumber INT; SET @IncrementNumber = 1;
        BEGIN TRAN
        BEGIN
        IF @Number = 0
        BEGIN            
         SET @Number =
         SELECT  ISNULL(MAX(Number),0)+@IncrementNumber
         from TESTNUMBERS
        END

            INSERT INTO TESTNUMBERS
                       ([ID]
                       ,[Name]
                       ,[Number])

            SELECT  ISNULL(MAX([ID]),0)+@IncrementID as [ID]                                            
                                               ,@Name
                                               ,@Number                                 
            FROM   TESTNUMBERS  
            --return the ID of the column inserted
            SELECT MAX([ID]) from TESTNUMBERS  
        END
        COMMIT TRAN
 END TRY
BEGIN CATCH
--TO DO      
END CATCH
END    
GO         

我如何改进和纠正这个 SP？

Answer 1

试试这个——

CREATE PROCEDURE dbo.usd_TEST_STOREDPROC

      @Name NVARCHAR(50)
    , @Number INT = 0
    , @ID INT   

AS BEGIN

    SET NOCOUNT ON;

    BEGIN TRY

        DECLARE 
              @IncrementID SMALLINT = 1 
            , @IncrementNumber INT = 1 

        BEGIN TRAN BEGIN

            SELECT @Number = ISNULL(MAX(Number), 0) + @IncrementNumber
            FROM dbo.TESTNUMBERS
            WHERE @Number = 0

            INSERT INTO dbo.TESTNUMBERS([ID], [Name], [Number])
            SELECT 
                  ISNULL(MAX([ID]), 0) + @IncrementID                                            
                , @Name
                , @Number                                 
            FROM dbo.TESTNUMBERS

            SELECT MAX([ID]) 
            FROM dbo.TESTNUMBERS

        END

        COMMIT TRAN

    END TRY

    BEGIN CATCH
    END CATCH

END    

Answer 2

        CREATE PROCEDURE SP_TEST
        @Name           NVARCHAR(50),
        @Number         INT = 0,
        @ID INT      
        AS
        BEGIN
          SET NOCOUNT ON
        BEGIN TRY
                DECLARE @IncrementID SMALLINT; SET @IncrementID=1;   
                DECLARE @IncrementNumber INT; SET @IncrementNumber = 1;
                BEGIN TRAN
                BEGIN
                IF @Number = 0
                *BEGIN            
                 **SET @Number =(SELECT  ISNULL(MAX(Number),0)+@IncrementNumber from TESTNUMBERS)***
                END

                    INSERT INTO TESTNUMBERS
                               ([ID]
                               ,[Name]
                               ,[Number])

                    SELECT  ISNULL(MAX([ID]),0)+@IncrementID as [ID]                                            
                                                       ,@Name
                                                       ,@Number                                 
                    FROM   TESTNUMBERS  
                    --return the ID of the column inserted
                    SELECT MAX([ID]) from TESTNUMBERS  
                END
                COMMIT TRAN
         END try
         **BEGIN CATCH
          ROLLBACK TRAN
        END CATCH**  
         end

您的存储过程中有两个语法错误

1. 当您通过 sql select 查询为任何变量赋值时，您应该添加圆括号。

2. 我想你忘记了 try 块之后的 catch 块，否则谁会捕捉你的异常并在错误后执行必要的事务:)，另外你的程序有很好的逻辑，保持它。对于语法谷歌在那里....