title: Entity Framework: Invalid column name
body: <p>I have problem with this <code>Conference</code> table. The error is : </p>
  
  <blockquote>
    <p>Invalid column name 'Conference_ConferenceID'</p>
  </blockquote>
  
  <p><img src="https://i.stack.imgur.com/r3Nyl.png" alt="enter image description here"></p>
  
  <pre><code>namespace MeetingBoard.Model
  {
      using System;
      using System.Collections.Generic;
      using System.ComponentModel.DataAnnotations;
      using System.Linq;
      using System.Web.Script.Serialization;
  
      using MeetingBoard.Model.Helpers;
      using System.ComponentModel.DataAnnotations.Schema;
      /// &lt;summary&gt;
      /// A model of the Conference entity. Contains functionality to serialize the entity to JSON as well.
      /// &lt;/summary&gt;
      public class Conference
      {
          [Key]
          public int ConferenceID { get; set; }
  
          public string Title { get; set; }
          public string Content { get; set; }
          public int CreatorID { get; set; }
  
          public string Location { get; set; }
          public DateTime SubmissionDate { get; set; }
  
  
          [ForeignKey("CreatorID")]
          public virtual User Creator { get; set; }
  
          public int[] RelatedProjectsIDs { get; set; }
          public virtual ICollection&lt;ProjectTag&gt; RelatedProjectTags { get; set; }
  
          public DateTime CreatedOn
          {
              get { return (this.dateCreated == default(DateTime)) ? DateTime.UtcNow : this.dateCreated; }
              set { this.dateCreated = value; }
          }
          private DateTime dateCreated = default(DateTime);
  
          public virtual ICollection&lt;Group&gt; RelatedGroups { get; set; }
  
          public Conference()
          {
              RelatedGroups = new List&lt;Group&gt;();
          }
  
  
          /// &lt;summary&gt;
          /// Generates an object that can be serialized by the JSON serializer of MVC
          /// &lt;/summary&gt;
          /// &lt;param name="happening"&gt;An Conference.&lt;/param&gt;
          /// &lt;returns&gt;&lt;/returns&gt;
          public static Object ToJsonObject(Conference conference)
          {
              int[] project_ids = conference.RelatedProjectTags.Select&lt;ProjectTag, int&gt;(pt =&gt; pt.ProjectID).ToArray();
  
  
  
              return new Conference_JSON
              {
                  id = conference.ConferenceID,
                  title = conference.Title,
                  Content = conference.Content,
                  created_timestamp_UTC = Util.DateTimeToMilliTimeStamp(conference.CreatedOn),
                  SubmissionDate = conference.SubmissionDate,
                  Location = conference.Location,
  
                  creator_avatar = conference.Creator.Avatar,
                  creator_fullname = conference.Creator.Name,
                  creator_id = conference.Creator.UserID,
  
                  project_ids = project_ids,
  
              };
          }
          /// &lt;summary&gt;
          /// Instantiates a new Conference object based on the json data.
          /// &lt;/summary&gt;
          /// &lt;param name="json_data"&gt;The json data needs to have the structure as specified in the private Conference_JSON object.&lt;/param&gt;
          /// &lt;returns&gt;A new Conference object. The related projects are referenced using an integer array containing project ids.&lt;/returns&gt;
          public static Conference FromJson(String json_data)
          {
              JavaScriptSerializer serializer = new JavaScriptSerializer();
              Conference_JSON conference_object = serializer.Deserialize&lt;Conference_JSON&gt;(json_data);
  
              return FromJsonObject(conference_object);
  
          }
  
          /// &lt;summary&gt;
          /// Instantiates a new Conference object based on the private Conference_JSON object.
          /// &lt;/summary&gt;
          /// &lt;param name="json_data"&gt;The object needs to be an instance of the private Conference_JSON object.&lt;/param&gt;
          /// &lt;returns&gt;A new Conference object. The related projects are referenced using an integer array containing project ids.&lt;/returns&gt;
          public static Conference FromJsonObject(Object conference_object)
          {
              Conference_JSON conference_json = (Conference_JSON)conference_object;
  
              Conference conference = new Conference
              {
                  ConferenceID = conference_json.id,
                  Title = conference_json.title,
                  Content = conference_json.Content,
                  RelatedProjectsIDs = conference_json.project_ids,
                  Location = conference_json.Location,
                  SubmissionDate = conference_json.SubmissionDate,
  
              };
              return conference;
          }
  
          /// &lt;summary&gt;
          /// Defines the structure of the json objects that ar communicated to and from the Frontend.
          /// &lt;/summary&gt;
          private class Conference_JSON
          {
              /// &lt;summary&gt;
              /// The Conference identifier.
              /// &lt;/summary&gt;
              public int id;
              public string title;
              public string Content;
  
              /// &lt;summary&gt;
              /// An numeric representation of the time, in milliseconds from Unix Epoch, UTC timezone.
              /// &lt;/summary&gt;
              public double created_timestamp_UTC;
  
              public string creator_fullname;
              public int creator_id;
              public string creator_avatar;
  
              /// &lt;summary&gt;
              /// Related projects.
              /// &lt;/summary&gt;
              public int[] project_ids;
              public string Location;
              public DateTime SubmissionDate;
  
          }
      }
  }
  </code></pre>