sql server - Entity Framework 6.1 - Code-First One-to-Many on single entity: Can't map PK to FK? -

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i'm trying one-to-many on single table/entity using code first. entity looks , works fine:

public class stockindex {     [key]     [databasegenerated(databasegeneratedoption.identity)]     public int id { get; set; }      [stringlength(45, minimumlength = 3)]     public string name { get; set; }      [stringlength(500)]     public string description { get; set; }      public list<component> components { get; set; }      public stockindex parentstockindex { get; set; }     public list<stockindex> stocksubindices { get; set; }      public stockindex()     {         stocksubindices = new list<stockindex>();     } }

it creates table pk , fk, you'd expect:

create table [dbo].[stockindex] (     [id]                  int            identity (1, 1) not null,     [name]                nvarchar (45)  null,     [description]         nvarchar (500) null,     [parentstockindex_id] int            null,     constraint [pk_dbo.stockindex] primary key clustered ([id] asc),     constraint [fk_dbo.stockindex_dbo.stockindex_parentstockindex_id] foreign key ([parentstockindex_id]) references [dbo].[stockindex] ([id]) );

it works great. i've scaffolded crud , works. however, forces me fire additional query in controllers when doing edit, in order lookup , assign "parent" record new one. want access "parentstockindex_id" field in table can assign directly dropdown , skip lookup query. tried mapping it:

public class stockindex {     [key]     [databasegenerated(databasegeneratedoption.identity)]     public int id { get; set; }      [stringlength(45, minimumlength = 3)]     public string name { get; set; }      [stringlength(500)]     public string description { get; set; }      public list<component> components { get; set; }      public int parentstockindex_id { get; set; }      [foreignkey("parentstockindex_id")]     public stockindex parentstockindex { get; set; }      public list<stockindex> stocksubindices { get; set; }      public stockindex()     {         stocksubindices = new list<stockindex>();     } }

but exception when running it, when data seeded in dbcontext:

unable determine principal end of 'myapp.models.stockindex_parentstockindex' relationship. multiple added entities may have same primary key.

i'm sure i'm doing wrong, without using fluent, if possible.

you should use public int? parentstockindex_id { get; set; }, set parent not required (have seen question mark after int).


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