DataTable使用总结

1.DataTable数据去重

  static void Main(string[] args)
         {
             DataTable dt = new DataTable();//创建表
             DataColumn dc = null;//创建列
             int fieldCount = ;//列数
             int rowCount = ;//行数
             //以下两个循环只是模拟向dt中添加数据
             for (int i = ; i < fieldCount; i++)
             {
                 if (i==)
                 {
                     dc = dt.Columns.Add("ID", Type.GetType("System.String"));
                 }
                 else
                 {
                     dc = dt.Columns.Add(string.Format("第{0}列", i.ToString()), Type.GetType("System.String"));
                 }
             }
             for (int i = ; i < rowCount; i++)
             {
                 DataRow newRow = dt.NewRow();
                 for (int j = ; j < fieldCount; j++)
                 {
                     if (j==)
                     {
                         newRow["ID"] = Guid.NewGuid();
                     }
                     else
                     {
                         newRow[string.Format("第{0}列", j.ToString())] = j;
                     }
                 }
                 dt.Rows.Add(newRow);
             }
             //数据去重处理
             DataTable finalltable = dt.Clone();
             finalltable.Clear();
             var rows = from row in dt.AsEnumerable()
                        group row
                        by row["第1列"]//表示根据具体的哪一列进行去重
                        into myrow
                        select myrow.FirstOrDefault();
             foreach (DataRow row in rows)
             {
                 finalltable.ImportRow(row);
             }
         }

模拟添加的数据：

数据去重后的结果：

2.DataTable排序

                DataTable dtTop100Total = new DataTable();
                DataRow[] rows = dtTop100Total.Select("", "int型的排序字段 DESC");
                DataTable t = dtTop100Total.Clone();
                t.Clear();
                foreach (DataRow row in rows)
                {
                    t.ImportRow(row);
                }
                dtTop100Total = t;

3.向DataTable中添加属于另一个DataTable的DataRow

                 DataTable dtSame = SQLHelper.ExecuteTableSQL(SqlQuery);//数据源
                 DataRow[] drSource = dtSame.Select(“过滤条件”, "排序字段 DESC/ASC");
                 DataTable dtTarget = dtSame.Clone();//复制数据源表结构
                 DataRow drTarget = dtTarget.NewRow();//创建新行
                 drTarget.ItemArray = drSource[0].ItemArray;//赋值
                 dtTarget.Rows.Add(drTarget);//添加

4.gridView绑定DataTable

DataTable dt = new DataTable();
            dt.Columns.Add("htl_cd");
            dt.Columns.Add("htl_nm");

            Random r = new Random();
            for (int i = ; i < ; i++)
            {
                DataRow dr = dt.NewRow();
                dr[] = r.Next(, );
                dr[] = r.Next(, );
                dt.Rows.Add(dr);
            }
            this.gridControl1.DataSource = dt;
            this.gridView1.PopulateColumns(); //显示gridCOntrol　数据