How can I store user data after login without asking the database to show this data?
ASP.NET Profile Providers looks like the thing you're looking for - especially if you're already using membership / role providers.
A more general article on Profile Properties: MSDN
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This sounds like a classic use of Session .
ASP.NET session state allows you to persist and retrieve values ββfor the user when the user moves ASP.NET pages in a web application. HTTP is a stateless protocol. This means that the web server treats every HTTP request for the page as an independent request. The server does not know the values ββof the variables that were used during previous requests. ASP.NET session state identifies requests from the same browser for a limited time as a session and provides the ability to persist variable values ββthroughout the session. By default, ASP.NET session state is enabled for all ASP.NET applications.
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