c# - getting records from list based on category -

query:

list<vwbooktitlekitssummary> thesekits = (from k in _datacontext.vwbooktitlekitssummaries                                                       k.datekitends > datetime.now && k.datekitstarts <= datetime.now && k.isdeleted == false                                                        orderby k.kitorder, k.kitcode descending                                                       select k).tolist(); 

thesekits got 6 results below (the highlighted ones):

i want query returns 1 item each category example want records k1503, t1503 i.e.

i want first record start k , first record start t

i tried following:

list<vwbooktitlekitssummary> thesekits = (from k in _datacontext.vwbooktitlekitssummaries                                                       k.datekitends > datetime.now && k.datekitstarts <= datetime.now && k.isdeleted == false && (k.kitcode.startswith("k"))                                                       orderby k.kitorder, k.kitcode descending                                                       select k).take(1).tolist();  list<vwbooktitlekitssummary> qry = (from k in _datacontext.vwbooktitlekitssummaries                            k.datekitends > datetime.now && k.datekitstarts <= datetime.now && k.isdeleted == false && (k.kitcode.startswith("t"))                            orderby k.kitorder, k.kitcode descending                            select k).take(1).tolist(); thesekits.addrange(qry); 

this return records kitcode - k1503, t1503

instead of writing 2 queries , using addrange can done in 1 query, please.

this should give 1 record per category, starting letters in category.

list<vwbooktitlekitssummary> firstcategorythesekits = _datacontext      .vwbooktitlekitssummaries.where(k => k.datekitends > datetime.now        && k.datekitstarts <= datetime.now && k.isdeleted == false).orderby(k => k.kitorder)      .thenbydescending(k => k.kitcode).groupby(k => k.kitcode[0]).select(grps => grps.first)      .tolist(); 

if want t or k, can add condition follows:

list<vwbooktitlekitssummary> firstcategorythesekits = _datacontext      .vwbooktitlekitssummaries.where(k => k.datekitends > datetime.now       && k.datekitstarts <= datetime.now && k.isdeleted == false       && (k.kitcode[0] == 't' || k.kitcode[0] == 'k')).orderby(k => k.kitorder)      .thenbydescending(k => k.kitcode).groupby(k => k.kitcode[0])      .select(grps => grps.first).tolist(); 

sorry query in concise notation, instead of query notation.