IdentityDbContext如何配置迁移

Question

Very similar to IdentityDbContext how to run migrations , but nothing there seemed to solve my issues. I've done my research, and there doesn't seem to be much info out there on using IdentityDbContext with migrations.

Some background... I inherited a web app that uses Entity Framework (which I'm not really that familiar with). I wasn't sure what libraries the packages.config was missing. I eventually got that sorted and found it used Entity Framework. I currently have it set to use 6.2.0 and the app seems to work fine.

The original developer had implemented IdentityDbContext and was using automatic migrations. He also had a DbMigrationsConfiguration implementation already defined, which I've added some seed queries to.

I've been using the automatic migrations so far, but I know it's not recommended for production. And I've had a couple times where I had to enable data loss to get the app to deploy, so that's probably why I shouldn't be using it.

This led me to Code First Migrations with an existing database , specifically to set up migrations for an existing schema. That's where I'm lost. It doesn't seem like any of those instructions work for IdentityDbContext . Here's what I've tried:

PM> Enable-Migrations
No context type was found in the assembly 'WebApp'.

PM> Enable-Migrations -ProjectName DataLayer
No context type was found in the assembly 'DataLayer'.

So, this led me to questioning whether IdentityDbContext would even work. So, next I tried changing my context to inherit from DbContext , which also meant having to add DbSet properties for users and roles so that my code would compile (though I never tested to see whether the app still worked). Now, here's what I tried:

PM> Enable-Migrations -ProjectName DataLayer
Migrations have already been enabled in project 'DataLayer'. To overwrite 
the existing migrations configuration, use the -Force parameter.

PM> Add-Migration InitialCreate –IgnoreChanges -ProjectName DataLayer
No migrations configuration type was found in the assembly 'DataLayer'. (In 
Visual Studio you can use the Enable-Migrations command from Package Manager 
Console to add a migrations configuration).

Am I reading this right? It can find a migrations configuration, but then it can't? Does anyone test these tools?

Ok, so then I decide to take the recommendation of using -Force:

PM> Enable-Migrations -ProjectName DataLayer -Force
Code First Migrations enabled for project DataLayer.

PM> Add-Migration InitialCreate –IgnoreChanges -ProjectName DataLayer
The project 'WebApp' failed to build.

And, as it says, the project failed to build because my existing DbMigrationsConfiguration implementation got overwritten. My existing implementation had a constructor that took some data for the seed queries. So, just for testing I decided not to worry about those seed queries, so I kept the auto-generated configuration and updated my app code to compensate. Now on to creating the initial migration:

PM> Add-Migration InitialCreate –IgnoreChanges -ProjectName DataLayer
System.IO.FileNotFoundException: Could not load file or assembly 
'Microsoft.AspNet.Identity.Core, Version=2.0.0.0, Culture=neutral, 
PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system 
cannot find the file specified.
File name: 'Microsoft.AspNet.Identity.Core, Version=2.0.0.0, 
Culture=neutral, PublicKeyToken=31bf3856ad364e35'

So, I already had Microsoft.AspNet.Identity.Core 2.2.1 installed to DataLayer through NuGet, but apparently it wasn't added as a reference in the DataLayer project. Added it in and let's try yet again:

PM> Add-Migration InitialCreate –IgnoreChanges -ProjectName DataLayer
System.Data.Entity.ModelConfiguration.ModelValidationException: One or more 
validation errors were detected during model generation:

DataLayer.IdentityUserLogin: : EntityType 'IdentityUserLogin' has no key 
defined. Define the key for this EntityType.
DataLayer.IdentityUserRole: : EntityType 'IdentityUserRole' has no key 
defined. Define the key for this EntityType.
IdentityUserLogins: EntityType: EntitySet 'IdentityUserLogins' is based on 
type 'IdentityUserLogin' that has no keys defined.
IdentityUserRoles: EntityType: EntitySet 'IdentityUserRoles' is based on 
type 'IdentityUserRole' that has no keys defined.

I assume these errors have to do with me switching IdentityDbContext to DbContext .

I don't really know where to go from here and I'm kind of frustrated. It really doesn't seem like this is going to work. If I really do have to change my IdentityDbContext over to a DbContext every time I add a migration, that's just unacceptable.

Even if I did get this to work, it seems convoluted when it's easy to write straight SQL DDL scripts. I suppose the advantage is migrations cover multiple versions of upgrades, but that can be handled with DDL scripts and a version number table, so that's not really an issue either.

Should I just try to give up using migrations? Or maybe Entity Framework completely?

Edit:

I found No context type was found in the assembly EF6 which explained why IdentityDbContext wasn't working. Apparently Microsoft.AspNet.Identity.Core doesn't get added as a reference, which seemed odd because I was kind of expecting the reference to be added with NuGet. But, that only solves the Enable-Migrations issue. Still has the no migration configuration error on Add-Migration.

Answer 1

Well, I think I have it all fixed. So, on top of the Enable-Migrations tool apparently swallowing missing references instead of telling you about them, the Add-Migration tool apparently needs -ConfigurationTypeName in order to find the configuration. Not entirely sure why, since Enable-Migrations was able to find the configuration without this. But as long as it works, that's all I care about.