Unable to cast object of type 'Collections.Generic.List`1[Microsoft.EntityFrameworkCore.Query.IIncludableQueryable`2 to type Generic.ICollection

Question

I am trying to add a property of a class from a query. I have two classes "Article & Source with manytomany relationship. source:

 public class Source
    {
        public Source()
        {
            this.Id = Guid.NewGuid();
        }

        public Guid Id { get; set; }
        public int ApiId { get; set; }

        public string? FullName { get; set; }
        public string? Bio { get; set; }

        public virtual ICollection<Article> Articles { get; set; }

                }

article :

 public class Article
    {
        public Article()
        {
            this.Id = Guid.NewGuid();
        }

        public Guid Id { get; set; }
        public int ApiId { get; set; }

        public string Title { get; set; }
        public string Summary { get; set; }

        public double Rating { get; set; }

        public DateTime? AirDate { get; set; }

        public virtual ICollection<Source> Cast { get; set; }

    }

in my method, first I do a split then a query. I want to add the results of the query to the property Cast of my class Article

 public void AddArticle(string name, string summary = null, string sources = " ", double rating = 5, DateTime? airDate = null)
        {
            using (var db = this._dataContextFactory.Create())
            {

                var sourcesDb = sources.Split(',').Select(a => db.Sources.Where<Source>(s => s.FullName == a).Include(s => s.Articles)).ToList();

                db.Articles.Add(new Article()
                {
                    Cast = (ICollection<Source>)sourcesDb.ToList(),
                    AirDate = airDate,
                    Rating = rating,
                    Summary = summary,
                    Title = name
                }); ; 
                
                db.SaveChanges();
                }
           
        }

when I execute the code I have the following error :

exception {"Unable to cast object of type 'System.Collections.Generic.List1[Microsoft.EntityFrameworkCore.Query.IIncludableQueryable2[test1Project.Models.Source,System.Collections.Generic.ICollection1[test1Project.Models.Article]]]' to type 'System.Collections.Generic.ICollection1[test1Project.Models.Source]'."} System.InvalidCastException

Thank you for your help

Answer 1

Thank you , I edited my method to var arrayOfString = sources.Split(','); var sourcesDb =db.Sources.Where(s => arrayOfString.Contains(s.FullName)).Include(s => s.Articles).ToList(); and it works . Thanks again –