c# - dynamic linq join groupjoin selectmany generic result -

i want able utilize dynamic linq c# queries join, groupjoin, selectmany incorporating defaultifempty() results, , want homecoming typed results, i.e., iqueryable , older select method.

i've amalgamated source code several sources , set on blog:

http://bradfultonprogramming.blogspot.com/2014/10/dynamic-linq-joins-groupjoin-selectmany.html