WPF

I have a SL/WPF application that populates a datagrid.  The button contains this code:

MyDomainContext context = new MyDomainContext();
dataGrid1.ItemsSource = context.DBTables;
context.Load(context.GetTwoDataBasesQuery());


The DomainServices.cs contains:

public IQueryable<DBTable>GetTwoDataBases()
{
return this.ObjectContext.DBTables;
}
 This code works fine but returns all columns in the context
I need to return only two columns so changed is as follows


public IQueryable<DBTable>GetTwoDataBases()
        {
           
            return GetDBTables().Select(m => new { m.col1, m.col2 });
            
        }
But code has errors, does not accept the "return" .
 how do I get col1 and col2?
Many thanX

public class Job : _Base
{
    private string _JobName = string.Empty;
    public string JobName
    {
        get { return _JobName; }
        set 
        {
            if (_JobName != value)
            {
                _JobName = value;
                RaisePropertyChanged("JobName");
            }
        }
    }

    private string _JobNumber = string.Empty;
    public string JobNumber
    {
        get { return _JobNumber; }
        set
        {
            if (_JobNumber != value)
            {
                _JobNumber = value;
                RaisePropertyChanged("JobNumber");
            }
        }
    }

    private ObservableCollection<Employee> _Employees;
    public ObservableCollection<Employee> Employees
    {
        get { return _Employees; }
        set
        {
            if (_Employees != value)
            {
                if (_Employees != value)
                {
                    _Employees = value;
                    RaisePropertyChanged("Employees");
                }
            }
        }
    }

    private Employee _SelectedEmployee;
    public Employee SelectedEmployee
    {
        get { return _SelectedEmployee; }
        set
        {
            if (_SelectedEmployee != value)
            {
                if (_SelectedEmployee != value)
                {
                    _SelectedEmployee = value;
                    RaisePropertyChanged("SelectedEmployee");
                }
            }
        }
    }

    public Job()
    {
        Employees = new ObservableCollection<Employee>();
    }
}

public class Employee : _Base
{
    private string _EmployeeName = string.Empty;
    public string EmployeeName
    {
        get { return _EmployeeName; }
        set
        {
            if (_EmployeeName != value)
            {
                _EmployeeName = value;
                RaisePropertyChanged("EmployeeName");
            }
        }
    }

    private bool _IsChecked = false;
    public bool IsChecked
    {
        get { return _IsChecked; }
        set
        {
            if (_IsChecked != value)
            {
                _IsChecked = value;
                RaisePropertyChanged("IsChecked");
            }
        }
    }
}       

<DataGrid ItemsSource="{Binding Jobs}"
            SelectedItem="{Binding SelectedJob}"
            AutoGenerateColumns="False">

    <DataGrid.Columns>
        <DataGridTextColumn Header="Job Name" Binding="{Binding JobName}" />
        <DataGridTextColumn Header="Job Number" Binding="{Binding JobNumber}" />
    </DataGrid.Columns>

    <DataGrid.RowDetailsTemplate>
        <DataTemplate>

            <StackPanel Orientation="Vertical">

                <DataGrid ItemsSource="{Binding Employees}"
                            SelectedItem="{Binding SelectedEmployee}"
                            AutoGenerateColumns="False">

                    <DataGrid.Columns>
                        <DataGridCheckBoxColumn Binding="{Binding IsChecked}"/>
                        <DataGridTextColumn Binding="{Binding EmployeeName}"/>
                    </DataGrid.Columns>

                </DataGrid>

                <Button Margin="5"
                        Height="23"
                        Width="75"
                        HorizontalAlignment="Left"
                        Content="Remove"/>

            </StackPanel>


        </DataTemplate>
    </DataGrid.RowDetailsTemplate>

</DataGrid>

public class MainWindowViewModel : _Base
{
    private ObservableCollection<Job> _Jobs;
    public ObservableCollection<Job> Jobs
    {
        get { return _Jobs; }
        set 
        {
            if (_Jobs != value)
            {
                if (_Jobs != value)
                {
                    _Jobs = value;
                    RaisePropertyChanged("Jobs");
                }
            }
        }
    }

    private Job _SelectedJob;
    public Job SelectedJob
    {
        get { return _SelectedJob; }
        set
        {
            if (_SelectedJob != value)
            {
                if (_SelectedJob != value)
                {
                    _SelectedJob = value;
                    RaisePropertyChanged("SelectedJob");
                }
            }
        }
    }

    public MainWindowViewModel()
    {
        this.PropertyChanged += new PropertyChangedEventHandler(MainWindowViewModel_PropertyChanged);
    }

    void MainWindowViewModel_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
    {
        if (e.PropertyName.Trim().ToLower() == "ischecked")
        {
            int x = 1;
        }
    }
}