SQL SERVER - Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding

Question

i got a little problem in my SQL Query. The following error is :

 Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding.

And here is my SQL Query

ALTER PROC sp_savepresence
@Username char(20),
@Image text
AS
BEGIN
------------
DECLARE  @PresStatus CHAR,
         @DateDiff INT,
         @ClockIn DATETIME,
         @InsertData varchar(20) = 'TranSavePresence';
        IF NOT EXISTS(SELECT Username FROM PresenceTransaction WHERE Username=@Username AND ClockOut IS NULL)
        BEGIN
            BEGIN TRANSACTION @InsertData
                INSERT INTO PresenceTransaction
                (
                    Username,
                    [Image],
                    PresenceStatus,
                    WorkHour,
                    ClockIn,
                    ClockOut
                )
                VALUES
                (
                    @Username,
                    @Image,
                    'N',
                    0,
                    getdate(),
                    NULL
                )
END
ELSE
BEGIN
    SELECT @ClockIn = ClockIn, @DateDiff = DateDiff(MINUTE, @ClockIn, getDate()) FROM PresenceTransaction WHERE Username=@Username AND ClockOut IS NULL AND PresenceStatus = 'N'
    IF @DateDiff IS NOT NULL    
    BEGIN
        SELECT @PresStatus = 'P'
    END
    ELSE
    BEGIN
        SELECT @PresStatus='N'
    END

    UPDATE PresenceTransaction 
        SET  
            PresenceStatus = @PresStatus,   
            WorkHour = @DateDiff,
            ClockOut = getDate()
        WHERE Username=@Username AND ClockOut IS NULL AND PresenceStatus = 'N'
END

------------
IF(@@Error <> 0)
BEGIN
    PRINT @@Error
    Rollback Tran @InsertData
    SELECT @@Error AS [Status]
END
ELSE    
BEGIN
    COMMIT TRAN @InsertData
    SELECT 'True' AS [Status]
END
END
GO

I have already read from some articles over the Internet, and some of articles, tell me to tune up my query. But i don't know where's the error point or maybe deadlock point, and I don't know how to tune up my query code. Thanks :)

Answer 1

Your stored procedure code conditionally starts a transaction, but commits if there was no error, rather than also checking if a transaction is in progress. See @@TRANCOUNT .

The fact you are trying to use a named transaction suggests there are other transactions likely to be active. Unless you are a guru ( and I'm not ) I would strongly suggest not using named nested transactions. It is hard to get right and often leads to confusing, hard to maintain code.