存储过程SQL-Server存在问题

Question

我有一个存储过程，我有一些问题。

我正在尝试查找我的表GOTWVotes ，如果VotedBy没有投票之前将表决投票（这是有效的），但是如果VotedBy之前已经投票，不要写入表并将VoteCount返回为1。

虽然它不写入表时VotedBy存在的价值VoteCount总是显得0

任何帮助，将不胜感激

CREATE PROCEDURE [dbo].[Votes]
    @VotedMember BIGINT,
    @VotedBy BIGINT

    AS
    DECLARE @votecount INT

    BEGIN TRY
    BEGIN TRANSACTION t_Transaction
    SELECT TOP 1 * FROM [GOTWVotes] WITH (TABLOCKX)

    SELECT @votecount = COUNT(*) FROM [dbo].[GOTWVotes] 
    WHERE [VotedBy] = @VotedBy
    IF @votecount = 0

    INSERT INTO 
        [dbo].[GOTWVotes] ([VotedMember],[VotedBy])
    VALUES
        (@VotedMember, @VotedBy)
    COMMIT TRANSACTION t_Transaction
    END TRY
    BEGIN CATCH
        SET @votecount = -1
        ROLLBACK TRANSACTION t_Transaction
    END CATCH
        RETURN @votecount

Answer 1

您可以执行以下代码

CREATE PROCEDURE [dbo].[Votes]
    @VotedMember BIGINT,
    @VotedBy BIGINT,
    @votecount INT OUTPUT

    AS

    BEGIN TRY
    BEGIN TRANSACTION t_Transaction

    SET @votecount = 0
    IF NOT EXISTS(SELECT 1 FROM [dbo].[GOTWVotes] 
    WHERE [VotedBy] = @VotedBy)
    BEGIN
        INSERT INTO 
        [dbo].[GOTWVotes] ([VotedMember],[VotedBy])
    VALUES
        (@VotedMember, @VotedBy)        
    END
    ELSE
    BEGIN
        SELECT @votecount = COUNT(*) FROM [dbo].[GOTWVotes] 
    WHERE [VotedBy] = @VotedBy
    END


    COMMIT TRANSACTION t_Transaction
    END TRY
    BEGIN CATCH
        SET @votecount = -1
        ROLLBACK TRANSACTION t_Transaction
    END CATCH

要调用上面的存储过程，您需要编写以下代码

DECLARE @votecount int
EXEC dbo.Votes @VotedMember = 0, -- bigint
    @VotedBy = 0, -- bigint
    @votecount = @votecount OUTPUT -- int

SELECT @votecount

Answer 2

这看起来很复杂。 我在想这样的事情：

CREATE PROCEDURE [dbo].[Votes] (
    @VotedMember BIGINT,
    @VotedBy BIGINT,
    @retval int output
) 
BEGIN

  INSERT INTO dbo.GOTWVotes (VotedMember, VotedBy)
    SELECT v.VotedMember, v.VotedBy
    FROM (VALUES (@VotedMember, @VotedBy)) v(VotedMember, VotedBy)
    WHERE NOT EXISTS (SELECT 1
                      FROM dbo.GOTWVotes gwv
                      WHERE gwv.VotedBy = v.VotedBy
                     );
  SET @retval = @@ROWCOUNT;
END;

我怀疑你想要做的事情也可以用约束来处理。