CODEWITHSUNDEEP
c#entity-frameworklinq
JamTay317
JamTay317

Reputation: 1017

Dynamic Entity Framework .ToList() returning error

I am trying to create a Query builder, and I have run into a a bit of a problem. I would like the end user to be able to choose what fields to they would like to be able to select.

my goad is to do something like this

public IQueryable Get(Type entityType)
{
    return _dbContext.Set(entityType).AsQueryable();
}

However when I try to do something like this _repository.Get(myType).ToList(); or really anything i do not compile, and get a message like this.

IQueryable' does not contain a definition for 'ToList' and no extension method 'ToList' accepting a first argument of type 'IQueryable' could be found (are you missing a using directive or an assembly reference?)

can someone please help?

Upvotes: 0

Views: 506

Answers (2)

ocuenca
ocuenca

Reputation: 39326

You need to use IQueryable<T> interface instead of IQueryable. IQueryable<T> inherits from IEnumerable<T>, and ToList is an extension method of IEnumerable<T>. IQueryable<T> has other extension methods like ToListAsync and its overloads.

If you're trying to create a generic repository then define your repository class as generic too. Doing that you could implement Get this way:

public class Repository<T> : IRepository<T> where T : class, 
{
   public IQueryable<T> Get()
   {
      return _dbContext.Set<T>();
   }
   //...
}

Upvotes: 2

JamTay317
JamTay317

Reputation: 1017

The answer here was that I couldn't use.ToList() with IQueryable but I could with IQueryable<T>. So what I had to do was add an Interface to the entities called IEntity and then do IQueryable<IEntity>().ToList();

Upvotes: 0

Related Questions