如何对DataTable进行检索和排序

显示结果

 

CustomerID	CompanyName	Country
WHITC	White Clover Markets	USA
TRAIH	Trail's Head Gourmet Provisioners	USA
THECR	The Cracker Box	USA
THEBI	The Big Cheese	USA
SPLIR	Split Rail Beer & Ale	USA
SAVEA	Save-a-lot Markets	USA
RATTC	Rattlesnake Canyon Grocery	USA
OLDWO	Old World Delicatessen	USA
LONEP	Lonesome Pine Restaurant	USA
LETSS	Let's Stop N Shop	USA
LAZYK	Lazy K Kountry Store	USA
HUNGC	Hungry Coyote Import Store	USA
GREAL	Great Lakes Food Market	USA

源代码

<%  @Import Namespace = " System.Data "   %>
<%  @Import Namespace = " System.Data.SqlClient "   %>
< HTML >
     < HEAD >
         < title > 使用DataTable进行检索和排序示例 </ title >
         < script language = " C# "  runat = " server " >

             void  Page_Load( object  sender, System.EventArgs e)
             {
                string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["ConnectionSqlServer"];
                string Sql = "SELECT CustomerID, CompanyName, Country FROM Customers";

                SqlConnection thisConnection = new SqlConnection(ConnectionString);
                SqlDataAdapter adapter = new SqlDataAdapter(Sql, thisConnection);

                // 创建DataTable对象
                DataTable table = new DataTable();

                // 填充数据到DataTable
                adapter.Fill(table);

                // 定义筛选条件字符串和排序字符串
                string strExpr = "Country = 'USA'";
                string strSort = "CompanyName DESC";

                // 获得经过筛选和排序后的数据
                DataRow [] resultRows = table.Select(strExpr, strSort);

                // 显示经过筛选和排序后的数据
                DisplayRows(resultRows, DisplayLabel);
            }
            
             //  显示DataRow数组中的内容
             public   void  DisplayRows(DataRow [] rows, Label label)
             {
                // 检查返回数据是否为空
                if(rows.Length <= 0)
                {
                    label.Text = "没有数据";
                    return;
                }
                label.Text = "";

                // 遍历DataRow数组的行和列，显示数据
                label.Text += "<Table border='1'>";
                label.Text += "<TR><TH>CustomerID</TH><TH>CompanyName</TH><TH>Country</TH></TR>";
                foreach(DataRow row in rows)
                {
                    label.Text += "<TR>";
                    for(int i=0; i<row.Table.Columns.Count; i++)
                    {
                        label.Text += "<TD>";
                        label.Text += row[i];
                        label.Text += "</TD>";
                    }
                    label.Text += "</TR>";
                }
                label.Text += "</Table>";
            }

         </ script >
     </ HEAD >
     < body >
         < form id = " Form1 "  method = " post "  runat = " server " >
             < H3 > 使用DataTable进行检索和排序示例 </ H3 >
             < asp:Label id = " DisplayLabel "  runat = " server " > Label </ asp:Label >
         </ form >
     </ body >
</ HTML >