Question

EF Reverse Code First Tool is generating a composite key

public vw_ResourcesMap()
    {
        // Primary Key
        this.HasKey(t => new { t.Refno, t.Obsolete }); // Why???

        // Properties
        this.Property(t => t.Refno)
            .HasDatabaseGeneratedOption(DatabaseGeneratedOption.None);

        this.Property(t => t.Name)
            .HasMaxLength(50);

        this.Property(t => t.LocnID)
            .IsFixedLength()
            .HasMaxLength(2);

        this.Property(t => t.Created_by)
            .HasMaxLength(50);

        // Table & Column Mappings
        this.ToTable("vw_Resources");
        this.Property(t => t.Refno).HasColumnName("Refno");
        this.Property(t => t.Name).HasColumnName("Name");
        this.Property(t => t.Head).HasColumnName("Head");
        this.Property(t => t.LocnID).HasColumnName("LocnID");
        this.Property(t => t.Obsolete).HasColumnName("Obsolete");
        this.Property(t => t.Created_by).HasColumnName("Created_by");
        this.Property(t => t.Version).HasColumnName("Version");
        this.Property(t => t.Rank).HasColumnName("Rank");
    }
}

I had to change the Primary Key declaration to this.HasKey(t => t.Refno) to map the relationship otherwise I would get the exception below.

The number of properties in the Dependent and Principal Roles in a relationship constraint must be identical.

Maybe it’s a bug — IDK

All is working, but would like to increase understanding and knowledge.

Thanks!

Answer 1

Database view doesn’t have primary key so EF tries to infer the key by using all non nullable columns which don’t use binary data types.