Cannot call the include method in Entity framework 7

Composite key Entity Framework 7 "The Property Cannot Be added to Entity Type

As requested, here is my solution:...public class OrganizationUnitMember { public int OrganizationUnitMemberId { get; set; } public int UserId { get; set; } public int OrganizationUnitId { get; set; } [ForeignKey("UserId")] public virtual OmegaUser User { get; set; } [ForeignKey("OrganizationUnitId")] public virtual Orga...

Entity Framework "An entity object cannot be referenced by multiple instances of IEntityChangeTracker"

I am getting the error ...An entity object cannot be referenced by multiple instances of IEntityChangeTracker...when trying to create a new entity and save it to the DB. ...I understand the error and how it normally occurs, but in this instance all I am doing is creating a new entity and adding a few ...int...s to it before saving, not adding any...

Entity Framework Core 1.1 OnModelCreating method not getting called

The problem you have is that you are naming the key and not the column here:...modelBuilder.Entity<TestTable>() .HasKey(t => t.Id) .HasName("TestTableId"); ...This creates a primary key and then names that key ...TestTableId.... What you should be doing is this:...modelBuilder.Entity<TestTable>() .Property(t => t.Id) .HasCol...

Include after Union method not working (Entity Framework Core 2)

You are accessing the IQueryable out of the context of the MyDbContext object. There is no db connection at that time. Make sure you do all db access withing the context of the MyDbContext (using scope):... public IEnumarable<User> GetItems() { IEnumarable<User> resultingList; using (var context = new MyDbContext()) { IQueryable<Us...

Calling Include in Entity Framework Core 2.0 makes the entity null if the property you are trying to include is null

The explanation is simple - there is discrepancy between your entity model and the database....When the FK is nullable like your ...OfficeId..., the relationship is optional, EF Core expects that the column can be null and uses ...left outer join... when retrieving the related data (requested via ...Include...)....But at some point you seem to adde...

Entity Framework Core - Call A Populate Extension Method Inside Include

You can create extension method for ...Student... collection itself...public static IQueryable<Student> IncludeExpertise(this IQueryable<Student> students) { return students .Include(s => s.Expertise) .ThenInclude(c => c.Teacher) .ThenInclude(p => p.License); }

Entity framework - Conditionally query related entities with derived types methods

I have three class:...public abstract class Conversation { public int Id { get; set; } public abstract bool HasUser(string userId); } public class PublicConversation : Conversation { public override bool HasUser(string userId) { return true; } } public class PrivateConversation : Conversation { public ICollection<...

Why is Entity Framework core loading entity's relations without adding include

I'm using EF core in a .net core project. After fetching data from ef context, the object's entity's (one-to-many etc...) are automatically loaded....Here's my code:... public TimeSheetActivity Get(int id) { DataSets.TimeSheetActivity dbActivity = db.TimeSheetActivities .Include(k => k.ProjectFil...

Entity Framework Core: Update() method INSERTs instead of UPDATEs on dependent entity

So, I think I might have found the issue....As noted above, I first did a search to retrieve the Vehicle, like this:...Vehicle vehicle = dbContext.Vehicles.FirstOrDefault(v => v.Username.Equals(username));...In this case, the Vehicle.Session, if one existed, was ...not... populated. Later on, I did the update as the code above shows, and it failed ...

Entity Framework Core 3.1 is throwing "Include has been used on non entity queryable" exception

An observation, your domain models PropertyToList and Property both have virtual properties. On top of that you are using Include operator to select these properties. ...This is not necessary, when property is defined with virtual, then it will be lazy loaded. So an Include is not needed. Lazy loading is not the recommended way, using include is be...