Code First migrations with multiple DbContexts fail when setting default schema

Question

I have two projects each with their own DbContext class that write to the same SQL Server 2012 database.

The DbContext classes are of the form:

public class BlogDbContext : DbContext
{
    public BlogDbContext()
        : base("CodeFirstTestConnString")
    {
    }

    public BlogDbContext(string connectionString)
        : base(connectionString)
    {
    }

    public DbSet<Blog> Blogs { get; set; }
    public DbSet<Post> Posts { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        //modelBuilder.HasDefaultSchema("blogtest");
    }
}

Using Code First Migrations I can create my tables in the (existing) database by executing the following in each project:

Enable-Migrations
Add-Migration Initial
Update-Database

This works fine, however if I add in the line commented out above to set the default schema (both projects use the same schema), Update-Database fails in the second project with the error "There is already an object named '__MigrationHistory' in the database.".

By running "Update-Database -Verbose" I can see that with the default schema changed, "CREATE TABLE [blogtest].[__MigrationHistory]" is executed for the second project; if I don't change the default schema it only tries to create this table the first time.

Is this a bug in Entity Framework, or am I missing something?

david l · Accepted Answer · 2016-05-03 10:51:33Z

Turns out that this is reported in Codeplex as a bug in EF6.

https://entityframework.codeplex.com/workitem/1685

The workaround shown there is to use a custom HistoryContext to set the default schema:

internal sealed class Configuration : DbMigrationsConfiguration<ConsoleApplication11.MyContext>
{
    public Configuration()
    {
        AutomaticMigrationsEnabled = false;

        SetHistoryContextFactory("System.Data.SqlClient", (c, s) => new MyHistoryContext(c, s));
    }
}

internal class MyHistoryContext : HistoryContext
{
    public MyHistoryContext(DbConnection existingConnection, string defaultSchema) : base(existingConnection, defaultSchema)
    {
    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        modelBuilder.HasDefaultSchema("foo");
    }
}

Collectives™ on Stack Overflow

Code First migrations with multiple DbContexts fail when setting default schema

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related