Question

First, I’ll describe my table structure a bit. There are two tables, FormField and Field.

A field can be linked to multiple formfields, but a formfield can only contain one field.

So I have this Linq Query:

var fields = from f in Data.Field.All()
                     join ff in formfields on f.Field_rid equals ff.Field_rid
                     select new
                     {
                         FormField = ff,
                         Field = f
                     };

Now, I am needing to put a distinct somewhere in there, but I can’t figure out where. Basically, I don’t want for the same Field to be returned to me more than once(so I never get a duplicate field). Where would I use the distinct function?

Answer 1

Distinct doesn’t seem to help you if you have multiple formFields per field and want to receive only distinct fields. But if you can think of some method to select only one formField from all field’s formFields then it can be easily done:

// assumimg that for all fields we want to receive only formField with minimum Field_rid
var fields = Data.Field.All()
               .Select(f => new 
                    {
                        Field = f,
                        FormField = formFields
                                        .Where(ff => ff.Field_rid == f.Field_rid)
                                        .OrderBy(ff => ff.Field_rid)
                                        .FirstOrDefault(),
                    });