Question

I am just starting out implementing ASP.NET MVC4 Simple Membership. In the template application
I see the following code:

namespace WebUx.Filters
{
    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
    public sealed class InitializeSimpleMembershipAttribute : ActionFilterAttribute
    {
        private static SimpleMembershipInitializer _initializer;
        private static object _initializerLock = new object();
        private static bool _isInitialized;

        public override void OnActionExecuting(ActionExecutingContext filterContext)
        {
            // Ensure ASP.NET Simple Membership is initialized only once per app start
            LazyInitializer.EnsureInitialized(ref _initializer, ref _isInitialized, ref _initializerLock);
        }

        private class SimpleMembershipInitializer
        {
            public SimpleMembershipInitializer()
            {
                Database.SetInitializer<UsersContext>(null);

                try
                {
                    using (var context = new UsersContext())
                    {
                        if (!context.Database.Exists())
                        {
                            // Create the SimpleMembership database without Entity Framework migration schema
                            ((IObjectContextAdapter)context).ObjectContext.CreateDatabase();
                        }
                    }

                    WebSecurity.InitializeDatabaseConnection("DefaultConnection", "UserProfile", "UserId", "UserName", autoCreateTables: true);

When I look around I see other examples that look something like this:

#region

using System.Data.Entity.Migrations;
using System.Linq;
using System.Web.Security;
using MVC4SimpleMembershipCodeFirstSeedingEF5.Models;
using WebMatrix.WebData;

#endregion

namespace MVC4SimpleMembershipCodeFirstSeedingEF5.Migrations
{
    internal sealed class Configuration : DbMigrationsConfiguration<UsersContext>
    {
        public Configuration()
        {
            AutomaticMigrationsEnabled = true;
        }

        protected override void Seed(UsersContext context)
        {
            WebSecurity.InitializeDatabaseConnection(
                "DefaultConnection",
                "UserProfile",
                "UserId",
                "UserName", autoCreateTables: true);

            if (!Roles.RoleExists("Administrator"))
                Roles.CreateRole("Administrator");

            if (!WebSecurity.UserExists("lelong37"))
                WebSecurity.CreateUserAndAccount(
                    "lelong37",
                    "password",
                    new {Mobile = "[phone]"});

            if (!Roles.GetRolesForUser("lelong37").Contains("Administrator"))
                Roles.AddUsersToRoles(new[] {"lelong37"}, new[] {"Administrator"});
        }
    }
}

Is there a reason why the template does the creation of the database in a filter and other
examples have some kind of migration file. What do people most often use? Seems to me that
the filter way of doing it would be fine for a start up application to get it working quick
but not so good for other kinds of applications.

Answer 1

I think at the end of the day it boils down to what you want to do.

1. Do you want to distribute the application + database(with schema) as separate entities. For this option you would need the user to mount the empty database with the schema on the sever and provide the connection string to the application or

2. Do you want to distribute the application and let it create the database schema during the initial installation/ configuration process (e.g how wordpress does it). For this option you would only require a connection to the database server. Entity framework will help you generate the required database schema.
   Also note that this code does not have to be placed inside a filter. If you read this MSDN documentation you will realize that action filters are always called before the action method runs. They did that to ensure that the membership is setup before you access the accounts controller actions.