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Question

Given the data model below I would like to select every ConfigurableItem that has a Schedule where IsActive =true.

I have looked at numerous examples re: associative tables and don't really get any of them due to the examples somehow magically ignoring the many-to-many association. There seems to be a lot of suggestion that I should be able to :

var f = from citem in context.ConfigurableItems
        where citem.ConfigurableItemSchedules.Schedule.IsActive == true
        select citem;

But that doesn't intellisense / compile. What am I missing here?

UPDATE:

Im using a .dbml autogenerated from drag and drop from server explorer (sql server) so below is some code that is auto generated that may help answer some of the comments. They're just truncated snippets of the generated fields.

public partial class ConfigurableItem : INotifyPropertyChanging, INotifyPropertyChanged
    {

        private static PropertyChangingEventArgs emptyChangingEventArgs = new PropertyChangingEventArgs(String.Empty);

        private long _ConfigurableItemIndexCode;

        private string _ItemRootPath;

        private string _ItemName;

        private string _HandlerAssembly;

        private string _HandlerType;

        private EntitySet<ConfigurableItemProperty> _ConfigurableItemProperties;

        private EntitySet<ConfigurableItemSchedule> _ConfigurableItemSchedules;

....

public partial class ConfigurableItemSchedule : INotifyPropertyChanging, INotifyPropertyChanged
{

    private static PropertyChangingEventArgs emptyChangingEventArgs = new PropertyChangingEventArgs(String.Empty);

    private long _ConfigurableItemIndexCode;

    private long _ScheduleIndexCode;

    private EntityRef<ConfigurableItem> _ConfigurableItem;

    private EntityRef<Schedule> _Schedule; 

Answer 1

I think you need:

var f = from citem in context.ConfigurableItems
        where citem.ConfigurableItemSchedules.Any(s=>s.Schedule.IsActive)
        select citem;

or something like that.

Answer 2

You are trying to reach Schedule but as ConfigurableItemSchedules itself has many rows (probably , I think) , compiler can not understand you need the schedules of which row.When you are using navigation properties in join you should be sure that the navigation property ends to just one row in destination Table or you should use .SelectMany(t=>...) or .any() to show compiler that you will select a collection of rows , may be it's better to start from the most bottom table like

var c = (from u in  context.Schedule
                     where u.IsActive == true
                     select u.ConfigurableItemSchedules.ConfigurableItems);