DataTable使用總結

1.DataTable數據去重

 1  static void Main(string[] args)
 2         {
 3             DataTable dt = new DataTable();//建立表
 4             DataColumn dc = null;//建立列
 5             int fieldCount = 4;//列數
 6             int rowCount = 4;//行數
 7             //如下兩個循環只是模擬向dt中添加數據
 8             for (int i = 0; i < fieldCount; i++)
 9             {
10                 if (i==0)
11                 {
12                     dc = dt.Columns.Add("ID", Type.GetType("System.String"));
13                 }
14                 else
15                 {
16                     dc = dt.Columns.Add(string.Format("第{0}列", i.ToString()), Type.GetType("System.String"));
17                 }
18             }
19             for (int i = 0; i < rowCount; i++)
20             {
21                 DataRow newRow = dt.NewRow();
22                 for (int j = 0; j < fieldCount; j++)
23                 {
24                     if (j==0)
25                     {
26                         newRow["ID"] = Guid.NewGuid();
27                     }
28                     else
29                     {
30                         newRow[string.Format("第{0}列", j.ToString())] = j;
31                     }
32                 }
33                 dt.Rows.Add(newRow);
34             }
35             //數據去重處理
36             DataTable finalltable = dt.Clone();
37             finalltable.Clear();
38             var rows = from row in dt.AsEnumerable()
39                        group row
40                        by row["第1列"]//表示根據具體的哪一列進行去重
41                        into myrow
42                        select myrow.FirstOrDefault();
43             foreach (DataRow row in rows)
44             {
45                 finalltable.ImportRow(row);
46             }
47         }

View Code

模擬添加的數據：

 

數據去重後的結果：

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中添加屬於另外一個DataTable的DataRow

                 DataTable dtSame = SQLHelper.ExecuteTableSQL(SqlQuery);//數據源
                 DataRow[] drSource = dtSame.Select(「過濾條件」, "排序字段 DESC/ASC");
                 DataTable dtTarget = dtSame.Clone();//複製數據源表結構
                 DataRow drTarget = dtTarget.NewRow();//建立新行
                 drTarget.ItemArray = drSource[0].ItemArray;//賦值
                 dtTarget.Rows.Add(drTarget);//添加

4

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(); //顯示gridCOntrol　數據