Lambda Expression for Many to Many relationship

Question

Based on the following Data Model, I want to write a "method syntax" lambda query that gives me a collection of RoleGroupMaps for a specific CMRole (in CMRoles table) and UIResource (in UIResources table).

I read this and this but can't get what I need.

Answer 1

assume urId is id of specific UIResource and listOfCMRoleIds is list of specified CMRole

context.UIResource.Where(x => x.ID == urId)
    .Join(context.UIResourceGroupMaps,
        x => x.ID, x => x.UIResourceID,
        (x, y) => y)
    .Join(context.UIResourceGroups,
        x => x.UIResourceGroupID, x => x.ID,
        (x, y) => y)
    .Join(context.RoleGroupMaps.Join(context.CMRoles.Where(x => listOfCMRolesIds.Contains(x.ID)),
                                   x => x.CMRoleID, x => x.ID,
                                   (x, y) => x),
        x => x.ID, x => x.UIResourceGroupID,
        (x, y) => y);