DataTable/Array Linq查询,groupby

DataTable Linq查询

1.查询DataRow

IEnumerable<DataRow> q1 = from r in dt.AsEnumerable()
                                      where r.Field<int>("ID") % 2 == 0
                                      select r;

2.查询某个字段

var query2 =
        from pl in dt.AsEnumerable( )
        select pl.Field<string>("Name");

 3.group by 

            var query = from r in dt.AsEnumerable()
                       group r by new { r1 = r.Field<int>("lcm_tap_id") } into m
                       select new { tap_id = m.Key.r1 };
            if (query.ToList().Count > 0)
            {
                query.ToList().ForEach(q =>
                    {
                        sbSdId.Append(q.tap_id + ",");
                    });
            }

 

 

Array Linq查询

int[] values = { 2,9,5,0,3,7,1,4,8,5};  
            var filtered =  
                from value in values  
                where value > 4  
                select value;