Users
(
 varchar UserName,
 varchar Password,
 binary  Permitions
)

User{string UserName, string Password, Permition Permitions: {...}}

db.Query<User>("Select UserName, Password, Permisions PermitionsFromTable
from Users WHERE UserName=@User AND Password =@Password", new { user,
password
}, user =>
 {
 user.Permitions = new Permition();
 user.Permitions.LoadPermitions("PermitionsFromTable");
 return user ;
});