How do you lock tables in SQL Server 2005, and should I even do it?

Question

This one will take some explaining. What I\'ve done is create a specific custom message queue in SQL Server 2005. I have a table with messages that contain timestamps for both a

Answer 1

You want to wrap your code in a transaction, then SQL server will handle locking the appropriate rows or tables.

begin transaction

--Grab the next message id
declare @MessageId uniqueidentifier
set @MessageId = (select top(1) ActionMessageId from UnacknowledgedDemands);

--Acknowledge the message
update ActionMessages
set AcknowledgedTime = getdate()
where ActionMessageId = @MessageId

commit transaction

--Select the entire message
...