How to convert LINQ query result to list and return generic List?

Question

I used generic ORM list example.

This is my table.

Person table

Guid
Name
LastName

and this is my struct class.

 public struct PersonItem   // database and class field names are the same
    {
        public Guid   Guid{ get; set; } 
        public string Name { get; set; }
        public string LastName { get; set; }
    }


  public struct PersonItems
    {
        public PersonItems()
        {
            Items = new List<PersonItem>();
        }

        public List<PersonItem> Items { get; set; }
    }

I'm using such and no problem but I always have to write field's

public PersonItems GetPersons()
        {
            var query = (from p in _DbEntities.t_Crew
                         select p).ToList();

            if (query != null)
            {
                foreach (var item in query)
                {
                    _PersonItems.Items.Add(new PersonItem
                        {
                            Guid = item.Guid,
                            Name = item.Name,
                            LastName = item.LastName

                        });
                }
            }

            return _PersonItems;

        }   


   public PersonItems GetPersons()
    {
        PersonItems personItems = new PersonItems();

        var query = from p in _DbEntities.t_Person
                    select p; >> this here query I need to convert linq query result to list

       personItems = query.ToList();
       return personItems ;
    }

error

Cannot implicitly convert type System.Collections.Generic.List' to PersonData.PersonItems'.

Solution 1

Try this

 public PersonItems GetPersons()
    {
        PersonItems personItems = new PersonItems();

        var query = (from p in _DbEntities.t_Person
                    select new PersonItems 
                    {
                        test = p.SomeName,
                        //Other Stuff
                        //...
                    }).ToList();
       return query;
    }

Solution 2

Comparing to the other version of your GetPersons() method, I think this line :

personItems = query.ToList();

should've been this way instead :

personItems.Items = query.ToList();

Update regarding the latest error. You can't assign list of t_Person to Item property which is of type list of PersonItem. Hence, your query need to be adjusted to return list of PersonItem :

var query = from p in _DbEntities.t_Person
            select new PersonItem
                        {
                            Guid = p.Guid,
                            Name = p.Name,
                            LastName = p.LastName
                        };

or other option is to change definition of Item property to list of t_Person :

public List<t_Person> Items { get; set; }

Comments

[har07]

the same error message?? if it is different please post the latest error message

[Serdar Şengül]

so yes I already tried it...but the same mistake again List<PersonItem> crewItems = new List<PersonItem>(); and I don't need that,because they already have a List class

[Serdar Şengül]

yes the same error message.. personItems.Items = query.ToList(); Error 1 Cannot implicitly convert type System.Collections.Generic.List<PersonData.t_Person>' to System.Collections.Generic.List<PersonData.Defination.Person‌​Item>' C:\TFS\Projec‌​ts\Ship\PersonData\P‌​ersons.cs 50 31 Pers‌​onData

[har07]

check my updated answer. Items property is of different type from what linq query returns, hence you got that conversion error

[Serdar Şengül]

because sometimes I'm using wcf service and table join,I can not use your proposal