DataTable 查询

using (SqlConnection con = new SqlConnection(ConStr))
            {
                try
                {
                    string sql = "select * from mainUser with(nolock) where 1=1";
                    con.Open();
                    DataTable userDt = new DataTable("userInfoDt");
                    SqlDataAdapter dap = new SqlDataAdapter(sql, con);
                    dap.Fill(userDt);
                    con.Close();
                    // 通过AsEnumerable() 实现linq查询接口
                    var data = userDt.AsEnumerable();
                    //linq条件查询
                    data = data.Where(a => a.Field<string>("uName") == "李四");
                    //linq结果集赋给新的DataTable
                    DataTable dd = data.CopyToDataTable();

                    //输出转DataTable dd
                    foreach (DataRow item in dd.Rows)
                    {
                        Console.WriteLine(item["uid"]);
                        Console.WriteLine(item["uName"]);
                        Console.WriteLine(item["uPhone"]);

                    }


                    //DataTable 筛选
                DataRow[] ddr = dd.Select("uName='张三'"); //"uName in ('张三','李四')"
                    foreach (DataRow item in ddr)
                    {
                        Console.WriteLine(item["uid"]);
                        Console.WriteLine(item["uName"]);
                        Console.WriteLine(item["uPhone"]);
                    }

                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.Message);
                }
                finally
                {
                    con.Close();
                }