Query ManyMany Collections....

[sitefinitysteve]

Tables are Locations, and Rotations

A rotation can have many locations, and visa versa

So if I have a locationID of 5, how do I query to get a list of all rotations who are linked to the LocationID 5?

I'm very confused :)  This is all I can think of....

var rotations = (from r in authContext.CommonRotations
                                 where r.CommonLocations.Where(x => x.LocationID == 3)
                                 select r);

...but that doesn't compile
CS0029: Cannot implicitly convert type 'System.Collections.Generic.IEnumerable<AuthDB.Model.CommonLocation>' to 'bool'

[Petko_I]

Hi Steve,

You can first find all CommonLocations with a LocationID of value 5 and then use SelectMany to load all related CommonRotations into one flattened result:

var query = context.CommonLocations
             .Where(x => x.LocationID == 5)
             .SelectMany(x => x.CommonRotations);

The idea is to use the filtering clause easily and then merge the lists of CommonRotations into a single collection.

We do hope the query provided is helpful. Should you have further questions, feel free to contact us.

All the best,
Petko_I
the Telerik team