Question

Here are the generated models:

public class DbObjectMap : EntityTypeConfiguration<DbObject>
{
    public DbObjectMap()
    {
        // Primary Key
        HasKey(t => new { t.Type, CompanyName = t.CompanyName, Id = t.Id });

        // Properties
        Property(t => t.Timestamp)
            .IsRequired()
            .IsFixedLength()
            .HasMaxLength(8)
            .IsRowVersion();

        Property(t => t.Type)
            .HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);

        Property(t => t.CompanyName)
            .IsRequired()
            .HasMaxLength(30);

        this.Property(t => t.Id)
            .HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);

        this.Property(t => t.Name)
            .IsRequired()
            .HasMaxLength(30);

        this.Property(t => t.VersionList)
            .IsRequired()
            .HasMaxLength(80);

        this.Property(t => t.LockedBy)
            .IsRequired()
            .HasMaxLength(132);

        // Table & Column Mappings
        this.ToTable("Object");
        this.Property(t => t.Timestamp).HasColumnName("timestamp");
        this.Property(t => t.Type).HasColumnName("Type");
        this.Property(t => t.CompanyName).HasColumnName("Company Name");
        this.Property(t => t.Id).HasColumnName("ID");
        this.Property(t => t.Name).HasColumnName("Name");
        this.Property(t => t.Modified).HasColumnName("Modified");
        this.Property(t => t.Compiled).HasColumnName("Compiled");
        this.Property(t => t.BlobReference).HasColumnName("BLOB Reference");
        this.Property(t => t.BlobSize).HasColumnName("BLOB Size");
        this.Property(t => t.DbmTableNo).HasColumnName("DBM Table No_");
        this.Property(t => t.Date).HasColumnName("Date");
        this.Property(t => t.Time).HasColumnName("Time");
        this.Property(t => t.VersionList).HasColumnName("Version List");
        this.Property(t => t.Locked).HasColumnName("Locked");
        this.Property(t => t.LockedBy).HasColumnName("Locked By");
    }
}

and:

{
    public ObjectTrackingMap()
    {
        // Primary Key
        HasKey(t => new { ObjectType = t.ObjectType, Id = t.Id, ChangeType = t.ChangeType });

        // Properties
        Property(t => t.Timestamp)
            .IsRequired()
            .IsFixedLength()
            .HasMaxLength(8)
            .IsRowVersion();

        Property(t => t.ObjectType)
            .HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);

        Property(t => t.Id)
            .HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);

        Property(t => t.ChangeType)
            .HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);



        // Table & Column Mappings
        ToTable("Object Tracking");
        Property(t => t.Timestamp).HasColumnName("timestamp");
        Property(t => t.ObjectType).HasColumnName("Object Type");
        Property(t => t.Id).HasColumnName("Object ID");
        Property(t => t.ChangeType).HasColumnName("Change Type");
        Property(t => t.ObjectTimestamp).HasColumnName("Object Timestamp");
    }
}

These two objects don’t have any relation in database tables. But they could be joined by
Object.Type = ObjectTracking.ObjectType and Object.ID = ObjectTracking.ObjectID fields.

Is there any way to create correct mapping in EF using FluentAPI for these two entities?

Answer 1

Easiest way is with Visual Studio – just open your EDMX file in graphic designer mode (double click it), activate Toolbox and Properties windows (in View menu on top), selct “Association” from Toolbox and drag-draw your relation from one table to another, than tweak it in the properties window.