Entity Framework 6 inverting column order for composite foreign keys -

i'm getting error:

(15,10) : error 3015: problem in mapping fragments starting @ lines 6, 15: foreign key constraint 'beta_alpha' table beta (alpha_2, alpha_1) table alpha (alpha_1, alpha_2):: insufficient mapping: foreign key must mapped associationset or entitysets participating in foreign key association on conceptual side.

the key information composite foreign key in beta (alpha_2, alpha_1) has columns inverted, alpha_2 first , alpha_1 second. appears bug in entity framework.

here entities:

public class alpha {     [key, column(order = 1)]     public string alpha_1 { get; set; }     [key, column(order = 2)]     public string alpha_2 { get; set; } }  public class beta {     [key, column(order = 1)]     public string beta_1 { get; set; }     [key, column(order = 2)]     public string alpha_2 { get; set; }     [required]     public string alpha_1 { get; set; }      [foreignkey("alpha_1, alpha_2")]     public virtual alpha alpha { get; set; } } 

note foreignkey attribute in beta correctly lists alpha_1 first.

here migration that's generated:

public partial class test : dbmigration {     public override void up()     {         createtable(             "dbo.betas",             c => new                 {                     beta_1 = c.string(nullable: false, maxlength: 128),                     alpha_2 = c.string(nullable: false, maxlength: 128),                     alpha_1 = c.string(nullable: false, maxlength: 128),                 })             .primarykey(t => new { t.beta_1, t.alpha_2 })             .foreignkey("dbo.alphas", t => new { t.alpha_2, t.alpha_1 }, cascadedelete: true)             .index(t => new { t.alpha_2, t.alpha_1 });          createtable(             "dbo.alphas",             c => new                 {                     alpha_1 = c.string(nullable: false, maxlength: 128),                     alpha_2 = c.string(nullable: false, maxlength: 128),                 })             .primarykey(t => new { t.alpha_1, t.alpha_2 });      }      public override void down()     {         dropforeignkey("dbo.betas", new[] { "alpha_2", "alpha_1" }, "dbo.alphas");         dropindex("dbo.betas", new[] { "alpha_2", "alpha_1" });         droptable("dbo.alphas");         droptable("dbo.betas");     } } 

even if manually update migration, still error because internal model inverting columns.

the bug appears related fact alpha_2 part of beta's composite primary key.

update studying link provided andrey molotkov below, removed foreignkey("alpha_1, alpha_2") attribute beta's alpha property , tried explicitly map in fluent api, still had exact same problem.

the next suggestion @ link explicitly set order using column attribute. think gets crux of problem. have property, alpha_2, participating in composite primary key, , composite foreign key, have able specify order each key independently.

public class beta {     [key, column(order = 1)]     public string beta_1 { get; set; }     [key, column(order = 2), foreignkey("alpha"), column(order = 1)]     public string alpha_2 { get; set; }     [required, foreignkey("alpha"), column(order = 2)]     public string alpha_1 { get; set; }      public virtual alpha alpha { get; set; } } 

but causes error because column attribute can appear once.

i think ef needs way specify order directly in key or foreignkey attribute.

you need change order of beta foreign key columns:

public class beta {     [key, column(order = 1)]     public string beta_1 { get; set; }     [key, column(order = 3), foreignkey("alpha")]     public string alpha_2 { get; set; }     [required, foreignkey("alpha"), column(order = 2)]     public string alpha_1 { get; set; }      public virtual alpha alpha { get; set; } }