如何在实体框架中添加种子方法

Question

I'm trying to run code-first migrations with Entity Framework. I enable, add, and update. When I update, it says it runs the seed method and there are no errors, but when I look at the data in the tables, there isn't any.

Here is my Seeder:

public static class Seeder
{
    public static void Seed(ApplicationDbContext context)
    {
        context.Props.AddOrUpdate(
            p => p.PropId,
            new Prop() { PropName = "sharpie" },
            new Prop() { PropName = "coin" },
            new Prop() { PropName = "playing cards" },
            new Prop() { PropName = "coffee mug" },
            new Prop() { PropName = "phone" },
            new Prop() { PropName = "keys" },
            new Prop() { PropName = "sunglasses" },
            new Prop() { PropName = "headphones" },
            new Prop() { PropName = "ring" },
            new Prop() { PropName = "lighter" }
            );

        context.Theories.AddOrUpdate(
            t => t.TheoryId,
            new Theory()
            {
               // TheoryId = 0,
                TheoryName = "Production",
                TheoryDescription = "Make it appear out of nowhere!"
            },
            new Theory()
            {
               // TheoryId = 1,
                TheoryName = "Vanish",
                TheoryDescription = "Make it vanish into thin air!"
            },
            new Theory()
            {
               // TheoryId = 2,
                TheoryName = "Transportation",
                TheoryDescription = "Make it vanish, and then reappear somewhere impossible!"
            },
            new Theory()
            {
               // TheoryId = 3,
                TheoryName = "Transformation", // This uses TWO props
                TheoryDescription = "Cause one of these items to change into the other item!"
            },
            new Theory()
            {
               // TheoryId = 4,
                TheoryName = "Multiplication",
                TheoryDescription = "Magically duplicate this item again and again!"
            },
            new Theory()
            {
               // TheoryId = 5,
                TheoryName = "Penetration", // This uses TWO props
                TheoryDescription = "Cause the two items to inexplicably pass through each other"
            },
            new Theory()
            {
               // TheoryId = 6,
                TheoryName = "Restoration",
                TheoryDescription = "Destroy the item in some way. Restore it."
            },
            new Theory()
            {
               // TheoryId = 7,
                TheoryName = "Levitation",
                TheoryDescription = "Make the item float in mid-air!"
            });

        //////////////////////////////////////////// The following seeds user data

        // ApplicationUser table seeder
        UserStore<ApplicationUser> userStore = new UserStore<ApplicationUser>(context);
        UserManager<ApplicationUser> userManager = new UserManager<ApplicationUser>(userStore);

        RoleStore<Role> roleStore = new RoleStore<Role>(context);
        RoleManager<Role> roleManager = new RoleManager<Role>(roleStore);

        if (!roleManager.RoleExists("Admin"))
            roleManager.Create(new Role { Name = "Admin" });

        if (!roleManager.RoleExists("User"))
            roleManager.Create(new Role { Name = "User" });

        IdentityResult result = null; // Sets the result to null. Used for error checking.

        /////////// Admin (1)
        ApplicationUser admin1 = userManager.FindByName("MagicRawb");

        if (admin1 == null)
        {
            admin1 = new ApplicationUser
            {
                FirstName = "Rob",
                LastName = "Greenwald",
                UserName = "magicrawb",
                Email = "magicrawb@test.com",
                Gender = Gender.Male
            };
        }

        result = userManager.Create(admin1, "asdfasdf");
        if (!result.Succeeded)
        {
            string error = result.Errors.FirstOrDefault();
            throw new Exception(error);
        }

        userManager.AddToRole(admin1.Id, "Admin"); // Add user1 to Admin role
        admin1 = userManager.FindByName("MagicRawb"); // Assign user1 data to variable user1

        /////////// Admin (2)
        ApplicationUser admin2 = userManager.FindByName("admin2");

        if (admin2 == null)
        {
            admin2 = new ApplicationUser
            {
                FirstName = "Bekah",
                LastName = "Cellz",
                UserName = "admin2",
                Email = "admin2@test.com",
                Gender = Gender.Female
            };
        }

        result = userManager.Create(admin2, "asdfasdf");
        if (!result.Succeeded)
        {
            string error = result.Errors.FirstOrDefault();
            throw new Exception(error);
        }

        userManager.AddToRole(admin2.Id, "Admin"); // Add user1 to Admin role
        admin1 = userManager.FindByName("admin2"); // Assign user1 data to variable user1

        /////////// User (1)
        ApplicationUser user1 = userManager.FindByName("user1");

        if (user1 == null)
        {
            user1 = new ApplicationUser
            {
                FirstName = "Lance",
                LastName = "Burton",
                UserName = "user1",
                Email = "user1@test.com",
                Gender = Gender.Male
            };
        }

        result = userManager.Create(user1, "asdfasdf");
        if (!result.Succeeded)
        {
            string error = result.Errors.FirstOrDefault();
            throw new Exception(error);
        }

        userManager.AddToRole(user1.Id, "User"); // Add user1 to Admin role
        user1 = userManager.FindByName("user1"); // Assign user1 data to variable user1

        /////////// User (2)
        ApplicationUser user2 = userManager.FindByName("user2");

        if (user2 == null)
        {
            user2 = new ApplicationUser
            {
                FirstName = "David",
                LastName = "Stone",
                UserName = "user2",
                Email = "user2@test.com",
                Gender = Gender.Male
            };
        }

        result = userManager.Create(user2, "asdfasdf");
        if (!result.Succeeded)
        {
            string error = result.Errors.FirstOrDefault();
            throw new Exception(error);
        }

        userManager.AddToRole(user1.Id, "User"); // Add user1 to Admin role
        user2 = userManager.FindByName("user2"); // Assign user1 data to variable user1

        context.SaveChanges();
    }
}

And here is my DbContext:

public ApplicationDbContext()
    : base("DefaultConnection", throwIfV1Schema: false)
{
    this.Configuration.LazyLoadingEnabled = false;
}

public static ApplicationDbContext Create()
{
    return new ApplicationDbContext();
}
public IDbSet<Prop> Props { get; set; }
public IDbSet<Theory> Theories { get; set; }
public IDbSet<NewTrick> NewTricks { get; set; }

I'm not quite sure what I'm doing wrong here. I'm glad to provide any info I might be missing.

Answer 1

you should add a configuration class like

internal class Configuration : DbMigrationsConfiguration<ApplicationDbContext>
{
    protected override void Seed(ApplicationDbContext context)
    {
          //seed code here
    }
}

and then have an initializer class like

public class MyInitializer : MigrateDatabaseToLatestVersion<ApplicationDbContext, Configuration>
{
}

and at the end set the initializer for your EF database in your application startup

Database.SetInitializer(new MyInitializer());

Answer 2

You have added UserRole to UserManager twice using the following line of code userManager.AddToRole(user1.Id, "User") This might be the cause for the conflict.

To be exact copy the above code you posted, on a new file and look at line number 159 and 184.