Return IQueryable from EF proxy object

Prevent EF from adding new child objects instead of just association when inserting new parent object?

When disconnected entities are reattached they are in Added state by default....You can change the state after attaching the exercise....public int CreateExercise(Exercise newExercise) { db.Exercises.Add(newExercise); // set all attached users to unchanged. db.ChangeTracker.Entries<User>().ToList().ForEach(p => p.State = EntityState.U...

EF Core join entity IQueryable with id IQueryable

You could do something like:...IQueryable<Entity> entityQuery = _context.Entities.Where(x => ...); IQueryable<int> idQuery = _context.AccessRights.Where(x => ...).Select(x => x.Id); entityQuery = entityQuery.Where(x => idQuery.Contains(x.Id)); ...This will get the result you're looking for without loading the ids into memory. But it may convert it ...

EF return null for some but EF Core return 0

Use ...DefaultIfEmpty...:...var q = bd.Prod .Where(o => o.xxx == yyy) .GroupBy(o => o.sss) .Select(g => new { ccc = g.Key, vvv = g.Sum(i => i.qqq), bbb = g.Sum(i => i.fff), nnn = g.Sum(i => i.ggg), }) .DefaultIfEmpty(null);

Web Api: Return JSON with EF Included Member Field Count but not Member Object Data

There are several options. Below are two of them: ...You might consider ...adding view models... - classes with the exact set of properties you would like to return to UI. You just need to ...map your entity records to them.... ...Or just ...mark the properties you'd like to hide... from being serialized to your ...JSON... or ...XML... endpoint res...

Entityframework 6.2.0 IQueryable.Count VS IQueryable.ToList().Count

I Finally figured out what's going on... The database tables are not linked together in the database (there are no relationship or constraints defined in the database itself) so the code doesn't execute the (inner join) part. However my classes on the other hand are well written so when I perform (ToList()) it automatically ignores the unbound rows...

Return list object with list object

When using entity framework people tend to (group-)join the tables themselves, while it is much easier to use the ...ICollections... instead....First of all: ...stick to the Entity Framework Code-First Conventions!...For example:... Every ...CarMake... has zero or more ...CarModels.... You decided to declare this as a ...List<CarModel>.... Are you ...

Can EF Core return IQueryable from Stored Procedure / Views / Table Valued Function?

EF cannot return IQueryable from a Stored Procedure because the database engine itself doesn't provide a mechanism for ...selectively... querying or manipulating execution of the script, you can't for instance do the following in SQL:...SELECT Field1, Field2 EXEC dbo.SearchForData_SP() WHERE Field2 IS NOT NULL ORDER BY Field3 ...The Stored Procedur...

How can I return IQueryable<TEntity> object from a mock object?

The initial issue is as you suspected with ...FirstOrDefaultAsync.... That extension expects the queryable to also have a ...IAsyncQueryProvider... in order to match async EF which the mock wont be by default....Remove ....GetQueryable()... as you do not need it. That member came from one of the samples to demonstrate how to use the mock library..

EF Core lazy loading proxies return null randomly instead of entities

You need to include UserToNavigation in your query as:...var delegation = rmsContext.Delegations.Include(x => x.UserToNavigation).Find(id); ...for accessing db data, try to use async/await. Your query will become:... var delegation = await rmsContext.Delegations.Include(x => x.UserToNavigation).FindAsync(id);

EF Core, return entry or create and return

To add to @JMP's answer:...See: ...DbSet.Add...In your code:...entry = db.mytable.Add(new mytable() { ID = id }); ...You assign the return of Add, which is EntityEntry<TEntity>, whereas earlier in your code, the "entry" variable is declared as TEntity. This is why you get the message:...Cannot implicitly convert type 'Microsoft.EntityFrameworkC...