R – Get list of users’ profiles values with standard fields, like email

I have the ASP.NET application. I use authentication with user profiles. I use SQL Server as a data provider. What I want to do is to get fill the GridView control with all the users in the system with additional profile information.

For now I do like this:

UserAccounts.DataSource = Membership.GetAllUsers();
UserAccounts.DataBind();

With that I can make a list with fields: UserName and Email. But now I want to add First and LastName fields which I store as a Profile informations.

I have found this post and tried to do like this:

ProfileInfoCollection profiles = ProfileManager.GetAllProfiles(ProfileAuthenticationOption.All);
DateTime lastActivity = profiles["some_username"].Email;

but this gives me only standard user fields, like Email, LastActivityDate, etc. Later I've tried to call the function for ever row in GridView table.

public string GetProfileValue(string name, string UserName)
{
    ProfileBase pb = ProfileBase.Create(UserName, true);
    return pb.GetPropertyValue(name).ToString();
}

But I don't think it is efficient to query database for every field with profile information. I was thinking of joining aspnet_Users and aspnet_Profile tables, but the FirstName and LastName fields are stored like this:

UserId | PropertyNames                   | PropertyValuesString | ....
----------------------------------------------------------------------
someId | FirstName:S:0:6:LastName:S:6:5: | ThomasSmith          | ....

so that means that I have to parse the strings to get my values.

My questions are:

1. Is it a good policy to query the aspnet_ tables directly using SELECT?
2. How to get the GridView which contain UserName, Email, LastActivityDate, FirstName, LastName (the standard and profile information together).