LINQ 查询

var query = from t in dt.AsEnumerable() 
           group t by new { t1 = t.Field<string>("areaid"), t2 = t.Field<string>("seq") } into m 
           select new 
           { 
             areaid = m.Key.t1, 
             seq = m.Key.t2, 
             house = m.First().Field<string>("house"), 
             rowcount = m.Count() 
           }; 

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