DataTable的列操作

 

      public DataTable GenerateTable()
        {
            //对Table1添加列名，并设置列值类型
            DataTable dt1 = new DataTable();//创建Table
            dt1.Columns.Add("ID", typeof(string));
            dt1.Columns.Add("NAME", typeof(string));
            dt1.Columns.Add("AGE", typeof(System.Decimal));
            dt1.Columns.Add("SEX", typeof(string));
            //此列放置的顺序
            dt1.Columns["SEX"].SetOrdinal(2);
            //对Table1进行设置KEY
            dt1.PrimaryKey = new DataColumn[] { dt1.Columns["ID"] };

            //对Tabel添加数值
            for (int i = 0; i < 5; i++)
            {
                DataRow dr = dt1.NewRow();
                dr["ID"] = "00" + i.ToString();
                dr["NAME"] = "00-" + i.ToString();
                dr["AGE"] = 15 + i;
                dr["SEX"] = "M";
                dt1.Rows.Add(dr);

            }
            //对数据行进行资料筛选
            dt1.Select("AGE > 20", "AGE ASC");
            //筛选
            dt1.DefaultView.RowFilter = "AGE > 20";
            dt1 = dt1.DefaultView.ToTable();
            //排序
            dt1.DefaultView.Sort = "ID DESC,AGE ASC";
            dt1 = dt1.DefaultView.ToTable();
            //添加一行空行 注：各列必须没有Key值限制
            dt1.DefaultView.AddNew();
            dt1 = dt1.DefaultView.ToTable();
            //只显示部分列，重复列值删去
            DataTable dtTemp = dt1.DefaultView.ToTable(true, new string[] { "SEX", "AGE" });

            return dt1;
        }