title: How to get List of items in item model using Include
body: <p><code>enter code here</code>I want to show a list of AppPlatforms in model, i have 4 tables App, AppPlatforms, Reviews, AppsArtifacts they have relationship. So i want to retrieve App data as well as AppPlatforms (like iOS and Android) of that App and then in AppPlatforms i want collections of Reviews and AppArtifacts.</p>
  
  <p>i have used this code to include</p>
  
  <p>when i use this </p>
  
  <pre><code>var app = dbContext.Apps
                    .Include("AppPlatforms.Reviews")
                    .Where(a =&gt; a.AppId == appId).ToList();
  </code></pre>
  
  <p>OR</p>
  
  <pre><code>var app = dbContext.Apps
                    .Include("AppPlatforms.Artifacts")
                    .Where(a =&gt; a.AppId == appId).ToList();
  </code></pre>
  
  <p>individually it is included, but when i use this</p>
  
  <pre><code>var app = dbContext.Apps
                    .Include("AppPlatforms.Reviews")
                    .Include("AppPlatforms.Artifacts")
                    .Where(a =&gt; a.AppId == appId).ToList();
  </code></pre>
  
  <p>then i got an error i.e InnerException = {"Unknown column 'Extent1.AppId' in 'on clause'"}</p>
  
  <p>Here are my tables.</p>
  
  <pre><code> public class App
      {
          [Key]
          public int AppId { get; set; }
          public string Name { get; set; }
          public bool? IsActivated { get; set; }
          public bool? Status { get; set; }
          public string UserId { get; set; }
          public DateTime UploadedDate { get; set; }
          [ForeignKey("UserId")]
          public virtual IdentityUser IdentityUser { get; set; }
  
          public int? CategoryId { get; set; }
          [ForeignKey("CategoryId")]
          public virtual Category Category { get; set; }
          public int? SubCategoryId { get; set; }
          [ForeignKey("SubCategoryId")]
          public virtual SubCategory SubCategories { get; set; }
  
          public virtual ICollection&lt;AppPlatform&gt; AppPlatforms { get; set; }
  
      }
  
  
   public class AppPlatform
      {
          [Key]
          public int AppsPlatformId { get; set; }
          public string AlternativeName { get; set; }
          public string Version { get; set; }
          public string DownloadLink { get; set; }
          public DateTime LastUpdated { get; set; }
          public DateTime? ReleaseDate { get; set; }
          public string Description { get; set; }
          public bool IsActive { get; set; }
          public float FileSize { get; set; }
          [DefaultValue(0)]
          public int AppId { get; set; }
          [ForeignKey("AppId")]
          public virtual App App { get; set; }
          public int PlatformId { get; set; }
          [ForeignKey("PlatformId")]
          public virtual Platform Platforms { get; set; }
          public virtual ICollection&lt;Review&gt; Reviews { get; set; }
          public virtual ICollection&lt;AppsArtifact&gt; Artifacts { get; set; }
  
      }
  
  
  public class AppsArtifact
      {
          [Key]
          public int Id { get; set; }
          public int AppsPlatformID { get; set; }
          [ForeignKey("AppsPlatformID")]
          public virtual AppPlatform AppPlatform { get; set; }
  
          public int ArtifactId { get; set; }
  
          [ForeignKey("ArtifactId")]
          public virtual Artifact Artifact { get; set; }
          public AppArtifactType Type { get; set; }
      }
  
   public class Review
      {
          [Key]
          public int ReviewId { get; set; }
          public string Description { get; set; }
          public int Value { get; set; }
          public int Risk { get; set; }
          public ReviewStatus Status { get; set; }
          public DateTime ReviewDate { get; set; }
  
          public int? AppPlatformId { get; set; }
          [ForeignKey("AppPlatformId")]
          public virtual AppPlatform AppPlatform { get; set; }
  
          public string ReviewerId { get; set; }
  
          [ForeignKey("ReviewerId")]
          public virtual IdentityUser IdentityUser { get; set; }
          public int LevelId { get; set; }
          [DefaultValue(1)]
          public bool IsActive { get; set; }
  
  
          [ForeignKey("LevelId")]
          public virtual Level Levels { get; set; }
      }
  </code></pre>