Table for type specific mapping (TPC) in EF4.4
I am trying to create a TPC project on EF 4.4.
I have a set of classes that are already mapped to existing tables and adding a new set with the same structure, which should map to different tables, with non-overlapping IDs.
So, here's a pretty much new design for the old classes (without the new type of hierarchy I'm about to add).
public abstract class HierarchyLevel
{
public virtual int Id { get; set; }
public string Name { get; set; }
}
public class MainHierarchyLevel : HierarchyLevel { }
public abstract class HierarchyItem
{
public int Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public virtual HierarchyLevel Level { get; set; }
}
public class MainHierarchyItem : HierarchyItem { }
public abstract class HierarchyTreeItem
{
public int Id { get; set; }
public virtual HierarchyTreeItem ParentTreeItem { get; set; }
public virtual HierarchyItem Parent { get; set; }
public virtual HierarchyItem Child { get; set; }
}
public class MainHierarchyTreeItem : HierarchyTreeItem { }
No matter what I do with the config, EF always makes the table name up, eg. I am getting a request like
SELECT
[Extent1].[Id] AS [Id],
'0X0X' AS [C1],
[Extent2].[Name] AS [Name],
[Extent2].[Description] AS [Description],
[Extent2].[Level_Id] AS [Level_Id]
FROM [dbo].[HierarchyItems] AS [Extent1]
INNER JOIN [dbo].[HierarchyItems1] AS [Extent2] ON [Extent1].[Id] = [Extent2].[Id]
Where HierarchyItems1 is compiled by EF.
Here's an example of what I am doing with the config:
public class HierarchyItemsConfiguration : EntityTypeConfiguration<HierarchyItem>
{
public HierarchyItemsConfiguration()
{
Property(hierarchyItem => hierarchyItem.Id).HasColumnName("Id").IsRequired();
Property(hierarchyItem => hierarchyItem.Name).HasColumnName("Name").IsRequired();
Property(hierarchyItem => hierarchyItem.Description).HasColumnName("Description").IsOptional();
}
}
public class MainHierarchyItemsConfiguration : EntityTypeConfiguration<MainHierarchyItem>
{
public MainHierarchyItemsConfiguration()
{
Map(mb =>
{
mb.MapInheritedProperties();
mb.ToTable("HierarchyItems");
});
ToTable("HierarchyItems");
HasKey(hierarchyItem => hierarchyItem.Id);
HasRequired(hierarchyItem => hierarchyItem.Level).WithMany().Map(e => e.MapKey("Level_Id"));
}
}
Any ideas on setting it up correctly?
Thank!
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1 answer
Change the configuration as follows:
public class MainHierarchyLevelConfiguration : EntityTypeConfiguration<MainHierarchyLevel>
{
public MainHierarchyLevelConfiguration()
{
Map(mb =>
{
mb.MapInheritedProperties();
mb.ToTable("MainHierarchyLevels");
});
}
}
public class MainHierarchyItemsConfiguration : EntityTypeConfiguration<MainHierarchyItem>
{
public MainHierarchyItemsConfiguration()
{
Map(mb =>
{
mb.MapInheritedProperties();
mb.ToTable("MainHierarchyItems");
});
HasKey(hierarchyItem => hierarchyItem.Id);
HasRequired(hierarchyItem => hierarchyItem.Level).WithMany().Map(e => e.MapKey("Level_Id"));
}
}
public class HierarchyContext : DbContext
{
public DbSet<MainHierarchyLevel> MainHierarchyLevels { get; set; }
public DbSet<MainHierarchyItem> MainHierarchyItems { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Configurations.Add(new MainHierarchyLevelConfiguration());
modelBuilder.Configurations.Add(new MainHierarchyItemsConfiguration());
}
}
Running the following test program will create 2 tables - one for each of the two specific classes MainHierarchyLevel and MainHierarchyItem.
using (var db = new HierarchyContext())
{
var level = new MainHierarchyLevel { Name = "Level1" };
level = db.MainHierarchyLevels.Add(level);
var mh = new MainHierarchyItem { Name = "m1", Description = "m1 desc", Level = level };
db.MainHierarchyItems.Add(mh);
db.SaveChanges();
var query = from m in db.MainHierarchyItems
orderby m.Name
select m;
Console.WriteLine("All mains in the database:");
foreach (var item in query)
{
Console.WriteLine(item.Name);
}
Console.WriteLine("Press any key to exit...");
Console.ReadKey();
}
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