Each user as database user

Good day!I'm trying to implement my own MemebershipProvider.Problem is, that different users should be different database users. Not each user.Any idea, how to solve this? Because only way how to use some database user I know it is to change connection string...

Why dont you use Windows Authentication and let the Active Directory take care of your memberships. Is this an internal application?

|||It is not.

I already wrote one post about it and I will tell it again.

Application is based on classicla win application. The same database. Problem is, that usual database is made for ONE company. But I need more of them in the web application.
Easy way how to do this is to create tables for each user. Usual dbo.Something will be user.Somethig for each user.
If you fire SELECT * FROM Something, it always goes against YOUR me.Something.

Elsewhere I would need to remake whole database and each upgrade would have to be made twice for desktop (one-company) databse and for mine.