MigrationHistory as entity in DbContext in Entity Framework 7

Question

MigrationHistory as entity in DbContext in Entity Framework 7

.net-core c# ef-migrations entity-framework entity-framework-core

Question

I'm trying to get the (by Entity Framework generated) table __EFMigrationsHistoryas an entity into my database context:

In Entity Framework 6 this worked fantastically, but did anyone tried it in EntityFramework 7?

What I tried is, to just add a new class __EFMigrationsHistory - but it'd be too easy - there is already a table named __EFMigrationsHistory in the database (thanks...)

Then I read about that HistoryRow, I shall inherit a class from. So I created the class

public class MigrationsHistory : HistoryRow 
{ 
    //... constructor etc.
}

started a migration and: I got two migration-history-tables (but only the original one works)

So I read on and searched for interfaces and classes to implement/inherit from. I found SqlServerHistoryRepository - looks nice. I created an new database context inheriting from SqlServerHistoryRepository (like I'd have done it in EF6). - But this is not a context-class, so I can not add it in Startup.cs (like I did with my default applicationcontext)

So I checked the DbContext for maybe add the history-table somewhere (like in EF6), but there is nothing for adding the table to my context.

So: Anyone already tried to add the migration-history to his context? Anyone was successful?

Matthias Burger

Popular Answer

Mapping to the table by name should work (it is that easy), you just need to ensure you don't try to re-create it (e.g. by accidentally calling DbContext.Database.EnsureCreate())

class MyContext : DbContext
{
    public DbSet<AppliedMigration> AppliedMigrations { get; set; }
}

[Table("__EFMigrationsHistory")]
class AppliedMigration
{
    [Column("MigrationId")]
    public string Id { get; set; }

    [Column("ProductVersion")]
    public string EFVersion { get; set; }
}

bricelam

View more on Stack Overflow

wonea · Accepted Answer · 8/24/2017 12:40:43 PM

Whilst I experimented with bricelam's answer with no success with EF Core 2.0, in Microsoft.EntityFrameworkCore there's a method;

// .NET Core 1.0 + Platform Extensions
// Microsoft.EntityFrameworkCore.Relational, Version=1.1.0.0, PublicKeyToken=adb9793829ddae60

namespace Microsoft.EntityFrameworkCore
{
    public static class RelationalDatabaseFacadeExtensions
    {
        public static IEnumerable<string> GetAppliedMigrations(this DatabaseFacade databaseFacade);
    }
}

Call it as follows;

var dbcontext = new DbContext();
IEnumerable<string> history = dbcontext.Database.GetAppliedMigrations();

MigrationHistory as entity in DbContext in Entity Framework 7

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