EF4.3 beta1 "Map was called more than once for type 'ModelName' and at least one of the calls didn't specify the target table name"

Question

this below was working with EF 4.2 but getting an error with EF 4.3 Beta1 for a Table Per Hierarchy setup

 internal class ParentmodelConfiguration : BaseEntityConfiguration< Parentmodel>

    {

        public  ParentmodelConfiguration  ()

        {

            this.Map<Childmodel>(m => m.Requires("RequiredFlag").HasValue(false).IsRequired());

            this.Map< Childmodel2>(m => m.Requires(" RequiredFlag").HasValue(true).IsRequired());           

        }

 

 public class   Childmodel : Parentmodel

    {

    }

 public class   Childmodel2 : Parentmodel

    {

    }

  public abstract class  Parentmodel 

    {

Answer 1

I fixed this by creating a configuration class for each child, and putting the type discrimination mapping for each child in the child configuration.

Answer 2

Thanks Antoine for the tip, I just upgraded a project and this had me stumped.  Although this has to be a bug (don't you think?). But at least we can make it work for now. 

For the example above, something like this:

     internal class ParentmodelConfiguration : BaseEntityConfiguration
    {
        public ParentmodelConfiguration()
        {          
            // put your mappings here (properties, table, key)
        }
    }
    internal class ParentmodelConfiguration<TEntityType> : BaseEntityConfiguration where TEntityType : class
    {
        internal ParentmodelConfiguration(ParentmodelType parentModelType)
        {
            // would recommend an "int" discriminator            
            // int discriminatorValue = (int)parentMdoelType;            
            // but for a bool, you could have this
            bool discriminatorValue = parentModelType.Childmodel ? false: true;
            this.Map(m => m.Requires("RequiredFlag").HasValue(discriminatorValue));
        }
    }

    public enum ParentmodelType
    {
        Childmodel,
        Childmodel2
    }

    // call it with
    modelBuilder.Configurations.Add(new ParentmodelConfiguration());
    modelBuilder.Configurations.Add(new ParentmodelConfiguration(ParentmodelType.Childmodel));
    modelBuilder.Configurations.Add(new ParentmodelConfiguration(ParentmodelType.Childmodel2));