c# - EF6 Code First Key not auto incrementing -

i have class model:

public class results {     [key]     [databasegenerated(databasegeneratedoption.identity)]     public int id { get; set; }     public int gameid { get; set; }     public games game { get; set; }     public string notes { get; set; }     public virtual icollection<resultitems> resultitems { get; set; } } 

for reason id field not set auto increment per schema:

create table [dbo].[results]  (     [id]     int            not null,     [gameid] int            not null,     [notes]  nvarchar (max) null,      constraint [pk_dbo.results] primary key clustered ([id] asc),     constraint [fk_dbo.results_dbo.games_gameid]          foreign key ([gameid]) references [dbo].[games] ([id]) on delete cascade ); go  create nonclustered index [ix_gameid] on [dbo].[results]([gameid] asc); 

i've added:

protected override void onmodelcreating(dbmodelbuilder modelbuilder) {         modelbuilder.entity<results>().haskey(p => p.id).property(p => p.id).hasdatabasegeneratedoption(databasegeneratedoption.identity);         base.onmodelcreating(modelbuilder); } 

to db context still migrations not make field auto increment. can see i'm doing wrong?

thanks.

paul.

sql server not support alter column add identity feature. while table created , , don't want loss data , cant automaticly, table,drop column(ignore in ef), , recreate table or column ef, abd restore values