Question

I am in the middle of migrating from Linq2Sql to Entity Framework and I got really stuck on one thing.

I have one table MappingSet. Which has a PK, MappingSetId. Then I also have a table XpathMappingSet which has the same PK, MappingSetId. It is both an FK and a PK.

In then I have a property on MappingSet which is called XpathMappingSet. This is null of there is no corresponding row in the XpathMappingSet table.

How can I configure this? I tried the following, but that didn’t really work:

HasOptional(m => m.XpathMappingSet).WithRequired(m => m.MappingSet).Map(m => m.MapKey("MappingSetId"));

The exception I got was:

(66,6) : error 0019: Each property name in a type must be unique. Property name ‘MappingSetId’ was already defined.

This all worked well in L2S but I cannot get it to work using Entity Framework.

MappingSet

public partial class MappingSet : BaseEntity
    {
        public int MappingSetId { get; set; }
        public virtual XpathMappingSet XpathMappingSet { get; set; }
    }

XpathMappingSet

public partial class XpathMappingSet
{
    public int MappingSetId { get; set; }
    public virtual MappingSet MappingSet { get; set; }
}

Mapping of XpathMappingSet

public partial class XpathMappingSetMap : EntityTypeConfiguration<XpathMappingSet>
{
    public XpathMappingSetMap()
    {
        ToTable("XpathMappingSets");

        HasKey(m => m.MappingSetId);

    }
}

Mapping of MappingSet

public partial class MappingSetMap : EntityTypeConfiguration<MappingSet>
{
    public MappingSetMap()
    {
        ToTable("MappingSets");
        HasKey(m => m.MappingSetId);
        HasOptional(m => m.XpathMappingSet).WithRequired(m => m.MappingSet).Map(m=>m.MapKey("MappingSetId"));
    }
}

Answer 1

Okay, I solved it.

I changed the mapping for xpathmappingset to:

public partial class XpathMappingSetMap : EntityTypeConfiguration<XpathMappingSet>
{
    public XpathMappingSetMap()
    {
        ToTable("XpathMappingSets");

        HasKey(m => m.XpathMappingSetId);

        Property(m => m.XpathMappingSetId).HasColumnName("MappingSetId");
    }
}

it didn’t like the fact that it had the same name