如何指示实体框架基于当前数据库选择迁移？

Question

So when a developer starts up our application locally, it will be against a blank, localhost database. But in production we will first need to migrate all of the old ASP.NET Membership Framework tables and data to the new ASP.NET Identity framework tables.

How can I write EF6 migrations to consider this? Also, our existing production database has no __Migration table in it.

Answer 1

When moving from Identity to Membership with data to be ported from old tables : You can create the tables that are according to Identity schema using SQL scripts. Else if you change your app to use Identity, running and creating user a first time will create the tables for you via code first. You can then copy the data from the old tables through a console application or via SQL scripts.

If you want to run migrations to create a new Identity tables before you run your application, you can do it by running the following steps - Enable-Migrations - Add-Migration - Update-Database

This will create the empty tables for your according to your DbContext. If it extends from IdentityDbContext, it will create the tables according to Identity schema along with the _MigrationHistory table. Hope this helps