c# - Cannot insert explicit value for identity column in table 'ActivityInstances' when IDENTITY_INSERT is set to OFF -

i trying insert new activityinstance, not setting id, entity framework attempting insert id anyway.

the model creation , save command:

        var ai = new activityinstance         {             activityid = 1,             locationid = 1,             begindate = datetime.now,             expirationdate = datetime.now         };         dbcontext.activityinstances.add(activityinstance);         dbcontext.savechanges(); 

the model

public class activityinstance : ibusinessobject, ientity {     public int id { get; set; }     public int locationid { get; set; }     public string targetid { get; set; }     public int activityid { get; set; }     public datetime? begindate { get; set; }     public datetime? expirationdate { get; set; }     public guid? durableinstanceworkflowid { get; set; }     public int? triggeredbyid { get; set; }     public virtual activity activity { get; set; }     public virtual location location { get; set; }     public virtual msdsdatavalidation msdsdatavalidation { get; set; }     public virtual icollection<resultstransmittalquestionanswer> activityquestionanswers { get; set; }     public virtual icollection<resultstransmittalcontact> resultstransmittalcontacts { get; set; }     public virtual target target { get; set; }     public virtual correctiveactionplan correctiveactionplans { get; set; }     public virtual fmvisit fmvisit { get; set; }     public virtual acknowledgereport acknowledgereport { get; set; }     public virtual slcap slcap { get; set; }     public virtual fmvisitstudentrecordreview fmvisitstudentrecordreview { get; set; }     public virtual icollection<activityinstancereminder> activityinstancereminders { get; set; }     // public virtual instancestable instances { get; set; } } 

the mapping

    public activityinstancemap()     {         totable("activityinstances");         haskey(x => x.id);          property(t => t.id);         property(t => t.locationid);         property(t => t.targetid);         property(t => t.activityid);         property(t => t.begindate);         property(t => t.expirationdate);         property(t => t.durableinstanceworkflowid);         property(t => t.triggeredbyid);          hasoptional(x => x.target)             .withmany(x => x.activityinstances)             .hasforeignkey(x => x.targetid);          hasrequired(t => t.activity)             .withmany(t => t.activityinstances)             .hasforeignkey(t => t.activityid);          hasrequired(t => t.location)             .withmany(t => t.activityinstances)             .hasforeignkey(t => t.locationid);          hasoptional(t => t.acknowledgereport)             .withrequired(t => t.activityinstance);      } 

the table design

    create table [dbo].[activityinstances] (     [id] int identity(1,1) not null,      [durableinstanceworkflowid] uniqueidentifier null,     [targetid] nvarchar(128) null,     [locationid] int not null,      [activityid] int not null,      [begindate] datetime null,     [expirationdate] datetime null,     [triggeredbyid] int null,     constraint [pk_activityinstances_id] primary key clustered ([id] asc),      constraint [fk_activityinstances_tolocations] foreign key ([locationid]) references dbo.locations([id]),      constraint [fk_activityinstances_toactivities] foreign key ([activityid]) references dbo.activities([id]),     constraint [fkinstancetriggeredinstance] foreign key ([triggeredbyid]) references dbo.activityinstances([id]),     constraint [fk_activityinstances_todurableworkflowinstance] foreign key ([durableinstanceworkflowid]) references [system.activities.durableinstancing].instancestable([id]) ) 

and getting in output window. id value default integer 0.

 insert [dbo].[activityinstances]([id], [locationid], [targetid], [activityid], [begindate], [expirationdate], [durableinstanceworkflowid], [triggeredbyid])     values (@0, @1, null, @2, @3, @4, null, null) 

update modified activityinstance model first suggested answer has led me toward actual issue, though still have not solved it. recommendation modify activityinstance model setting below on id

    [databasegenerated(databasegeneratedoption.identity)]     public int id { get; set; } 

now getting error:

a dependent property in referentialconstraint mapped store-generated column. column: 'id'.

i looking @ optional 1 one relationship currently. acknowledge report table is:

create table [dbo].[acknowledgereports] ( [activityinstanceid] int not null, constraint [pk_acknowledgereportsid] primary key clustered ([activityinstanceid] asc) )

acknowledgereport model

public class acknowledgereport : iactivityinstance {     public int activityinstanceid { get; set; }      public virtual list<report> reports { get; set; }     public virtual activityinstance activityinstance { get; set; }  } 

and acknowledgereport mapping

    public acknowledgereportmap()     {         totable("acknowledgereports");         haskey(t => t.activityinstanceid);          property(t => t.activityinstanceid);           // relationships       } 

try adding attributes let know database generated

[key] [databasegeneratedattribute(databasegeneratedoption.identity)] public int id { get; set; }