How can I open .sdf (SQL Database) file

How can I open .sdf (SQL Database) file

I was hoping to be able to open .sdf file. I am using WebMatrix, I can
view the queries there. I can read the schema too. But how can I read the
file without using WebMatrix. Its SQL Server file not the Comptact
edition.
I have searched for web help (Through windows). But all in vain. I will
prefer any link or any method to read the basic queries.