Question

I need populate a Pure Junction Table (containing only FK to other tables) when an EntityDataSource _Inserted event is raised.

I have 3 Tables in my Database:

CmsJobs (JobId)
CmsJobsUsers (JobId FK, UserId FK)*
aspnet_Users (UserId)

*CmsJobsUsers is a PURE JUNCTION TABLE and it is not represented as an entity in the EF Model.

Here my code, I am NOT able to save this data in CmsJobsUsers.

protected void uxEntityDataSourceCreateJob_Inserted(object sender, EntityDataSourceChangedEventArgs e)
{
    Guid myUserListSelected = new Guid(uxListUsers.SelectedValue);// Guid for UserId in DropDownList 
    CmsJob myJob = (CmsJob)e.Entity; // My new Jobid
    aspnet_Users myUser = new aspnet_Users();
    myUser.UserId = myUserListSelected;
}

Any Ideas? Thanks for your help!

Here a useful resource:
But I am not able to implment it:
http://thedatafarm.com/blog/data-access/inserting-many-to-many-relationships-in-ef-with-or-without-a-join-entity/

Answer 1

You’re not showing your EDM, but your CmsJob entity should have a navigation property aspnet_Users and the aspnet_User entity should have a navigation property CmsJobs. The simplest way to insert an entity into the junction table you need to fetch a User from the DB, add a CmsJob to the users CmsJobs collection, and save the user.

Again, you are not showing your attempt to persist anything to the DB, so I will write up a suggestion:

protected void uxEntityDataSourceCreateJob_Inserted(object sender, EntityDataSourceChangedEventArgs e)
{
    using (var context = new YourEFObjectContext())
    {
        Guid myUserListSelected = new Guid(uxListUsers.SelectedValue);
        CmsJob myJob = (CmsJob)e.Entity; // My new Jobid
        aspnet_Users myUser = context.aspnet_Users.Single(u => u.UserId == myUserListSelected);
        myUser.CmsJobs.Add(myJob);
        context.SaveChanges();
    }
}