asp.net-mvc - how to check username and password from my own table?

Question

In asp.net webforms we can determine members or admins table for login like :

select * from tbladmins where username = @p1 and password = @p2

but in asp.net mvc it has own database , table and class .. Membership class connect to own table for check username and password ..

I want to know how can I use Membership class for my own admins table ?! I mean I want to check my own table on my own database by Membership class . but Membership use asp.net database on local server for checking username and password . by this way every site need 2 database for Account and other data like posts , news and etc ..

I have a table with this columns : id , username , password .

How can I check this table by Membership class ?