Linq not in select on datatable

Question

Hi i\'ve got 2 data tables (bannedlist,countrylist), both contains list of country names and cods in columns cc and country. I am trying to do a query where i can select cou

Answer 1

Except would work if you use it on sequences of the countries:

using System.Linq;
...

    var ccList = from c in ds.Tables[2].AsEnumerable()
                 select c.Field("Country"); 
    var bannedCCList = from c in ds.Tables[1].AsEnumerable()
                       select c.Field("Country");
    var exceptBanned = ccList.Except(bannedCCList);

If you need the full rows where the countries aren't banned, you could try a left outer join:

    var ccList = ds.Tables[2].AsEnumerable();
    var bannedCCList = ds.Tables[1].AsEnumerable();
    var exceptBanned = from c in ccList
                       join b in bannedCCList
                         on c.Field("Country") equals b.Field("Country") into j
                       from x in j.DefaultIfEmpty()
                       where x == null
                       select c;