Question about choosing linq and ToList ()

Question

I am having trouble returning a list by executing a SelectLINQ query . This is the request:

 var data = Repository<EducationString>
              .Find()
              .ToList() 
              .Select(p => new EducationStringModel() {
                      Id = p.Id,
                      Title = p.Title,
                      EducationDegree=p.EducationDegree })
              .ToList();

As you can see, I used ToList()2 times. I don’t know why, but when I delete the first one ToList(), I see this error, "The index was outside the array", but if there is ToList()no problem.

Would it help if I said what EducationDegreeto EducationStringModeleat IList<EducationDegree>?

Is there anyone who knows the reason?

@Mark: its L2O

if u need to see classes:

EducationStringModel {  private IList _educationDegree = List(); IList EducationDegree   {              {           if (_educationDegree == null)           {               _educationDegree = List();           }           return _educationDegree;       }       set {_educationDegree = ; }

}

public int? Id { get; set; }
public string Title { get; set; }

}

EducationString {

_title;    IList _educationExperiences;    IList _educationDegree;

virtual public string Title
{
    get { return _title; }
    set { _title = value; }
}

virtual public IList<EducationExperience> EducationExperiences
{
    get
    {
        if (_educationExperiences == null)
        {
            _educationExperiences = new List<EducationExperience>();
        }

        return _educationExperiences;
    }

    set
    {
        _educationExperiences = value;
    }

}

virtual public IList<EducationDegree> EducationDegree
{
    get
    {
        if (_educationDegree == null)
        {
            _educationDegree = new List<EducationDegree>();
        }
        return _educationDegree;
    }

    set
    {
        _educationDegree = value;
    }
}

}

Answer 1

? : Find()?

, ToList , LINQ-to-Objects, AsEnumerable() . Select ( L2O ). Find() - , LINQ- (, , : ). .