解决方法
几乎放弃对谷歌的研究,我设法从这里找到这个报价：
> http://msdn.microsoft.com/en-gb/data/jj591621.aspx#specific
哪个指定：
Let’s say we want to migrate our database to the state it was in after running our AddBlogUrl migration. We can use the
–TargetMigrationswitch to downgrade to this migration.Run the
Update-Database –TargetMigration: AddBlogUrlcommand in Package Manager Console.
This command will run the Down script for our AddBlogAbstract and AddPostClass migrations.If you want to roll all the way back to an empty database then you can use the
Update-Database –TargetMigration: $InitialDatabasecommand.
