Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

Locking a table from a stored procedure

Posted on 2007-11-20
2
Medium Priority
?
2,021 Views
Last Modified: 2012-08-13
I am trying to create a small online voting application in ASP.NET and I have the following stored proc that inserts an record into the VOTERS table and then updates the vote count in the CANDIDATE table.

Here is my question:
When I am updating the vote count, do I need to lock the CANDIDATE table? Every now and then, I will have 100+ users on the site simultaneously.

Also, if you have any other feedback/suggestion about my stored proc, please let me know.

Thanks.

--------------------------------------------------------------------------------------------------------------------

CREATE PROCEDURE dbo.TrusteeElection_CastBallot
(
      @ID varchar(11),
      @Candidate      int,
      @Type char(1),
      @Status char(1),
      @MachineIP varchar(50) = null,
      @MachineDNS varchar(50) = null,
      @ServerVariables nvarchar(1500) = null,
      @Success      bit OUTPUT
)
AS
      SET NOCOUNT ON;
      SET @Success = 0
      
BEGIN
      DECLARE @TranStarted   bit
      SET @TranStarted = 0
            
      IF( @@TRANCOUNT = 0 )
      BEGIN
            BEGIN TRANSACTION
            SET @TranStarted = 1
      END
      ELSE
            SET @TranStarted = 0
      
      INSERT INTO VOTERS
                  (ID, Type, Status, MachineIP, MachineDNS, ServerVariables)
      VALUES     (@ID,@Type,@Status,@MachineIP,@MachineDNS,@ServerVariables)
      IF( @@ERROR <> 0 )
      BEGIN
            GOTO Cleanup
      END

      UPDATE CANDIDATES SET TotalVotes = (SELECT TotalVotes + 1 FROM CANDIDATES WHERE ID = @Candidate) WHERE ID = @Candidate
      IF( @@ERROR <> 0 )
      BEGIN
            GOTO Cleanup
      END

      -- everything looks good, let's commit the transcation
      IF(@TranStarted = 1)
      BEGIN
            SET @TranStarted = 0
            SET @Success = 1
                  COMMIT TRANSACTION
      END
      RETURN

Cleanup:
      IF(@TranStarted = 1)
      BEGIN
            SET @TranStarted = 0
                  ROLLBACK TRANSACTION
      END
      RETURN
      
END
GO
0
Comment
Question by:IUAATech
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
2 Comments
 
LVL 70

Accepted Solution

by:
Scott Pletcher earned 2000 total points
ID: 20322710
>> When I am updating the vote count, do I need to lock the CANDIDATE table? <<

No, SQL will automatically lock (at least) the row(s) being UPDATEd.  
0
 

Author Comment

by:IUAATech
ID: 20322740
Thanks Scott.

This is the first time I am using TRANSACTION in a stored proc. If you get a chance, please let me know if I have missed something. Everything seems to work well when I tested it, but I still want an extra set of eyes to go through my code.
0

Featured Post

Free Backup Tool for VMware and Hyper-V

Restore full virtual machine or individual guest files from 19 common file systems directly from the backup file. Schedule VM backups with PowerShell scripts. Set desired time, lean back and let the script to notify you via email upon completion.  

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In this article we will learn how to fix  “Cannot install SQL Server 2014 Service Pack 2: Unable to install windows installer msi file” error ?
What if you have to shut down the entire Citrix infrastructure for hardware maintenance, software upgrades or "the unknown"? I developed this plan for "the unknown" and hope that it helps you as well. This article explains how to properly shut down …
Using examples as well as descriptions, and references to Books Online, show the documentation available for date manipulation functions and by using a select few of these functions, show how date based data can be manipulated with these functions.
Via a live example, show how to shrink a transaction log file down to a reasonable size.

688 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question