Read data from database in code behind (C#)
<%@ Page language="c#" src="AuthorBrowser.aspx.cs" AutoEventWireup="false" Inherits="AuthorBrowser" %> <HTML> <body> <form id="Form1" method="post" runat="server"> <asp:label id="Label1" style="Z-INDEX: 105; LEFT: 32px; POSITION: absolute; TOP: 24px" runat="server" Font-Size="X-Small" Font-Names="Verdana" Width="181px" Height="20px"> Select Author:</asp:label><asp:label id="lblResults" style="Z-INDEX: 106; LEFT: 32px; POSITION: absolute; TOP: 64px" runat="server" Font-Size="X-Small" Font-Names="Verdana" Width="384px" Height="168px"></asp:label><asp:dropdownlist id="lstAuthor" style="Z-INDEX: 102; LEFT: 184px; POSITION: absolute; TOP: 20px" runat="server" Font-Size="X-Small" Font-Names="Verdana" Width="171px" Height="22px" AutoPostBack="True"></asp:dropdownlist></form> </body> </HTML> <%-- using System; using System.Collections; using System.ComponentModel; using System.Data; using System.Drawing; using System.Web; using System.Web.SessionState; using System.Web.UI; using System.Web.UI.WebControls; using System.Web.UI.HtmlControls; using System.Data.OleDb; public class AuthorBrowser : System.Web.UI.Page { protected System.Web.UI.WebControls.Label Label1; protected System.Web.UI.WebControls.Label lblResults; protected System.Web.UI.WebControls.DropDownList lstAuthor; private string connectionString = "Provider=Microsoft.Jet.OLEDB.4.0; data source=" + System.Web.HttpContext.Current.Server.MapPath("EmployeeDatabase.mdb"); private void Page_Load(object sender, System.EventArgs e) { if (!this.IsPostBack) { FillAuthorList(); } } #region Web Form Designer generated code override protected void OnInit(EventArgs e) { InitializeComponent(); base.OnInit(e); } private void InitializeComponent() { this.lstAuthor.SelectedIndexChanged += new System.EventHandler(this.lstAuthor_SelectedIndexChanged); this.Load += new System.EventHandler(this.Page_Load); } #endregion private void FillAuthorList() { lstAuthor.Items.Clear(); // Define the Select statement. // Three pieces of information are needed: the unique id, // and the first and last name. string selectSQL; selectSQL = "SELECT FirstName, LastName, ID FROM Employee"; // Define the ADO.NET objects. OleDbConnection con = new OleDbConnection(connectionString); OleDbCommand cmd = new OleDbCommand(selectSQL, con); OleDbDataReader reader; // Try to open database and read information. try { con.Open(); reader = cmd.ExecuteReader(); // For each item, add the author name to the displayed // list box text, and store the unique ID in the Value property. while (reader.Read()) { ListItem newItem = new ListItem(); newItem.Text = reader["LastName"] + ", " + reader["FirstName"]; newItem.Value = reader["ID"].ToString(); lstAuthor.Items.Add(newItem); } reader.Close(); } catch (Exception err) { lblResults.Text = "Error reading list of names. "; lblResults.Text += err.Message; } finally { con.Close(); } } private void lstAuthor_SelectedIndexChanged(object sender, System.EventArgs e) { // Create a Select statement that searches for a record // matching the specific author id from the Value property. string selectSQL; selectSQL = "SELECT * FROM Employee "; selectSQL += "WHERE ID=" + lstAuthor.SelectedItem.Value + ""; // Define the ADO.NET objects. OleDbConnection con = new OleDbConnection(connectionString); OleDbCommand cmd = new OleDbCommand(selectSQL, con); OleDbDataReader reader; // Try to open database and read information. try { con.Open(); reader = cmd.ExecuteReader(); reader.Read(); lblResults.Text = "<b>" + reader["LastName"]; lblResults.Text += ", " + reader["FirstName"] + "</b><br>"; lblResults.Text += "ID: " + reader["ID"] + "<br>"; reader.Close(); } catch (Exception err) { lblResults.Text = "Error getting author. "; lblResults.Text += err.Message; } finally { con.Close(); } } } --%>
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