如何基于Entity Framework代码优先模型自动生成.mdf db（如果不存在）

Question

I have written the models and context class, successfully ran the initial migration and seeded and generated the local database on my machine. The problem is I am working on a collaborative project at University using Github and the .gitignore file ignores .mdf files (for obvious reasons).

My question: is there a way to automatically generate and seed the .mdf SQL Server database file on app start-up if it doesn't exist in the App_Data folder?

My context class looks like this:

public class ABFContext : DbContext
{
    public ABFContext() : base("ABFDatabase")
    {
        Database.SetInitializer(new CreateDatabaseIfNotExists<ABFContext>());
    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
    }

    public DbSet<BasketItem> BasketItems { get; set; }
    public DbSet<Catalogue> Catalogues { get; set; }
    // other entities omitted for clarity
}

Connection string like this:

<connectionStrings>
    <add name="DefaultConnection" 
         connectionString="Data Source=(LocalDb)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\aspnet-ABF-20190304080703.mdf;Initial Catalog=aspnet-ABF-20190304080703;Integrated Security=True" 
         providerName="System.Data.SqlClient" />
</connectionStrings>

Migrations config with seed data:

 internal sealed class Configuration : DbMigrationsConfiguration<ABF.DAL.ABFContext>
{
    public Configuration()
    {
        AutomaticMigrationsEnabled = false;
    }

    protected override void Seed(ABF.DAL.ABFContext context)
    {
        context.CustomerRoles.AddOrUpdate(x => x.Id,
              new CustomerRole() { Id = 1, Role = "Member - Current" },
              new CustomerRole() { Id = 2, Role = "Member - Previous" },
              new CustomerRole() { Id = 3, Role = "Customer" },
              new CustomerRole() { Id = 4, Role = "Sponsor" },
              new CustomerRole() { Id = 5, Role = "Staff/Volunteer" }
              );

        // other seed data omitted for clarity
    }
}

Answer 1

On EF 6: Use Database.SetInitializer method. (Untested code)

class MyInitializer : IDatabaseInitializer<MyContext>
{
    public void InitializeDatabase(MyContext context)
    {
        if (context.MyEntities.Any()) return;

        // add entities here
    }
}

class MyContext : DbContext
{
    public MyContext()
    {
        Database.SetInitializer(new MyInitializer());
    }
}

SetInitializer doc: https://docs.microsoft.com/en-us/previous-versions/visualstudio/gg679461(v=vs.113)

IDatabaseInitializer doc: https://docs.microsoft.com/en-us/dotnet/api/system.data.entity.idatabaseinitializer-1?view=entity-framework-6.2.0

Answer 2

I was able to achieve this by adding Database.Initialize(true); to the context class:

public class ABFContext : DbContext
{
    public ABFContext() : base("ABFDatabase")
    {
        Database.SetInitializer(new CreateDatabaseIfNotExists<ABFContext>());
        Database.Initialize(true);
    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
    }

    public DbSet<BasketItem> BasketItems { get; set; }
    public DbSet<Catalogue> Catalogues { get; set; }
}

Modifying the connection string to:

<add name="ABFDbConnection" 
     connectionString="Data Source=(LocalDb)\MSSQLLocalDB;Integrated Security=True" 
     providerName="System.Data.SqlClient" />
</connectionStrings>

And running the update-database EF command in the package manager console. This seeded and generated the .mdf SQL Server database file on a different machine using the same code-first model.