IsRequired(false) created same field name with additional 1

[gohckok11]

public class Table1
{
        public int Table1Id { get; set; }
        public string Name { get; set; }

        public virtual ICollection<Table2> MyTables { get; set; }
}

public class Table2
{
        public int Table2Id { get; set; }
        public int Table1Id { get; set; }
        [ForeignKey("Table1Id")]
        public virtual Table1 Table1 { get; set; }
}

protected override void OnModelCreating(ModelBuilder builder)
{
    builder.Entity<Table1>()
        .HasMany(e => e.MyTables)
        .WithOne(e => e.Table1)
        .IsRequired(false);
}

PostgresException: 42703: column t.Table1Id1 does not exist

The above code generated additional field that is invalid. Removing false in IsRequired() will operate normally. I am currently using Npgsql.EntityFrameworkCore.PostgreSQL v2.1.1.

[roji]

It seems reasonable for Table1Id1 to get created: you're defining an optional relationship from Table2 to Table1, explicitly specifying the foreign key to be Table1Id, but defining Table1Id to be non-nullable... Have you tried making Table1Id an int? intead of an int`?

Regardless, this issue doesn't seem like it's specific to Npgsql in any way (it would probably happen in Sqlite, SQL Server...) so it belongs in the EF Core repo, if you're still encountering issues please move it there.

[ajcvickers]

/cc @divega @AndriySvyryd This is not unreasonable behavior, but I expected an exception instead that said the FK wasn't nullable, so just pinging you guys to take a look.

[AndriySvyryd]

@ajcvickers This is by design. The explicit 'IsRequired' overrides the FK property set through the attribute.
We could consider logging this, but I don't think it would help, as we already log the creation of the shadow property and that wasn't seen by the user.

[divega]

@AndriySvyryd I think a warning might help other customers if not everyone.

[AndriySvyryd]

@divega it will also produce more log spam for customers that are ok with the behavior.

[divega]

I get that there is a compromise, but to me this one seems to be on the border of being invalid configuration. Do you think the chances that anyone would do this on purpose are high? I don't, but maybe I am missing something.

[ajcvickers]

It seems unlikely to me that this would be intentional, so a warning makes sense to me.

[AndriySvyryd]

Filed dotnet/efcore#12693