1.DataTable提供一个有用的方法Select()，它可以使用SQL表达式查询某行，Select()方法使用的表达式和select语句的Where子句的作用一样，其依据是DataTable中已经存在内在数据。

　　DataRow[] matchRows = ds.Tables["Products"].Select("discontinued=1");

 

1     protected void Page_Load(object sender, EventArgs e) 2     { 3         // Create the Connection, DataAdapter, and DataSet. 4         string connectionString = WebConfigurationManager.ConnectionStrings["Northwind"].ConnectionString; 5         SqlConnection con = new SqlConnection(connectionString); 6  7         string sqlProd = "SELECT ProductName, CategoryID,discontinued FROM Products"; 8  9         SqlDataAdapter da = new SqlDataAdapter(sqlProd, con);10         DataSet ds = new DataSet();11 12         try13         {14             con.Open();15             // Fill the DataSet with the Products table.16             da.Fill(ds, "Products");17         }18         finally19         {20             con.Close();21         }22 23         StringBuilder htmlStr = new StringBuilder("");24 25         DataRow[] matchRows = ds.Tables["Products"].Select("discontinued=1");26 27         foreach (DataRow childRow in matchRows)28         {29             htmlStr.Append("
");30             htmlStr.Append(childRow["ProductName"].ToString());31             htmlStr.Append("
");32         }33         htmlStr.Append("");34 35         // Show the generated HTML code.36         HtmlContent.Text = htmlStr.ToString();37     }

运行结果：

对比