how to maintain database concurrence?

My application uses sql for performing operation. something like conncetion.execute(query). so there is only conncetion object no recordset object or something like that .

i want to run multiple instence of my application so i want to maintain integrety of data. and i am looking for solution through sql for locking mechanism. so concurrent data access dont currept data.

I hope you have uderstand my requirement.Avoid locking whenever possible! Use optimistic concurrency (http://msdn.microsoft.com/library/default.asp?url=/library/en-us/odbc/htm/odbcoptimistic_concurrency.asp) instead of relying on locking.

-PatP