I'm using EF6 code first with ASP.NET Web API.
Suppose there are two model classes
public class RawMaterial {
public int ID { get; set; }
public string Name { get; set; }
}
public class Furniture {
public int ID { get; set; }
public string Name { get; set; }
public virtual ICollection<RawMaterial> RawMaterials { get; set; }
}
DbContext
public class FurnitureContext : DbContext {
public DbSet<RawMaterial> RawMaterials { get; set; }
public DbSet<Furniture> Furnitures { get; set; }
}
And in the initializer class,
protected override void Seed (FurnitureContext context) {
var glass = new RawMaterial { Name = "glass" };
var wood = new RawMaterial { Name = "wood" };
var paint = new RawMaterial { Name = "paint" };
context.RawMaterials.AddRange(new RawMaterial[] { glass, wood, paint });
var chair = new Furniture {
Name = "chair",
RawMaterials = new RawMaterial[] { wood, paint }
};
var coffeeTable = new Furniture {
Name = "coffee table",
RawMaterials = new RawMaterial[] { wood, glass }
};
context.Furnitures.AddRange(new Furnitures[] { chair, coffeeTable });
context.SaveChanges();
}
I encountered a run time error complaining "an item cannot be removed from fixed size array". So clearly the program's trying to remove wood from chair before adding it to coffeeTable. So I changed the initializations to use Lists, as
var chair = new Furniture {
Name = "chair",
RawMaterials = new List<RawMaterial> { wood, paint }
};
After that, I could clearly see that wood was indeed removed from one of the furnitures' RawMaterials.
I also tried selecting wood from the context by
var chair = new Furniture {
Name = "chair",
RawMaterials = new RawMaterial[] {
context.RawMaterials.Where(r => r.Name == wood.Name).FirstOrDefault()
}
};
The result is still the same.
So my question is: how can I add the test data such that wood is present in both chair and coffeeTable? I am aware that this is not typically how many-to-many relations are defined, since RawMaterial does not know of Furniture. Or should I define the models the other way?
Thank you.
Edit: I check the database tables in SQL Server Object Explorer, and the SQL for RawMaterial is
CREATE TABLE [dbo].[RawMaterials] (
[ID] INT IDENTITY (1, 1) NOT NULL,
[Name] NVARCHAR (MAX) NULL,
[Furniture_ID] INT NULL,
CONSTRAINT [PK_dbo.RawMaterials] PRIMARY KEY CLUSTERED ([ID] ASC),
CONSTRAINT [FK_dbo.RawMaterials_dbo.Furnitures_Furniture_ID] FOREIGN KEY ([Furniture_ID]) REFERENCES [dbo].[Furnitures] ([ID])
);
GO
CREATE NONCLUSTERED INDEX [IX_Furniture_ID]
ON [dbo].[RawMaterials]([Furniture_ID] ASC);
And the SQL for Furniture is
CREATE TABLE [dbo].[Furnitures] (
[ID] INT IDENTITY (1, 1) NOT NULL,
[Name] NVARCHAR (MAX) NULL,
CONSTRAINT [PK_dbo.Furnitures] PRIMARY KEY CLUSTERED ([ID] ASC)
);
So basically entity framework is not creating the database the way I need. That's why I cannot add wook to both chair and coffeeTable. How should I modify the Entity Models?
