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 = 4;//列数
            int rowCount = 4;//行数
            //以下两个循环只是模拟向dt中添加数据
            for (int i = 0; i < fieldCount; i++)
            {
                if (i==0)
                {
                    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 = 0; i < rowCount; i++)
            {
                DataRow newRow = dt.NewRow();
                for (int j = 0; j < fieldCount; j++)
                {
                    if (j==0)
                    {
                        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

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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

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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 = 0; i < 100; i++)
            {
                DataRow dr = dt.NewRow();
                dr[0] = r.Next(0, 1000);
                dr[1] = r.Next(0, 1000);
                dt.Rows.Add(dr);
            }
            this.gridControl1.DataSource = dt;
            this.gridView1.PopulateColumns(); //显示gridCOntrol　数据