mysqlcommand.aspx.cs

ASP C#代码实例 适合初学人士学习使用

using System;
using System.Collections;
using System.Configuration;
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.SqlClient;
using System.Xml;

namespace Example_5_1
{
	/// <summary>
	/// Summary description for MySqlCommand.
	/// </summary>
	public class MySqlCommand : System.Web.UI.Page
	{
		protected System.Web.UI.WebControls.Label ScalarLabel;
		protected System.Web.UI.WebControls.Label NonQueryLabel;
		protected System.Web.UI.WebControls.TextBox XmlReaderTextBox;
		private readonly string SQLCONNECTIONSTRING = ConfigurationSettings.AppSettings["SQLCONNECTIONSTRING"].ToString();

		private void Page_Load(object sender, System.EventArgs e)
		{			
			if(!Page.IsPostBack)
			{
				///使用ExecuteScalar()方法执行数据库查询
				ScalarLabel.Text = ExecuteScalarMySqlCommand().ToString();

				///使用ExecuteNonQuery()方法更新数据库，并显示更新后的结果
				ExecuteNonQueryMySqlCommand("My new name is ExecuteNonQuery");
				NonQueryLabel.Text = ExecuteScalarMySqlCommand().ToString();

				///使用ExecuteXmlReader()方法执行数据库查询，并显示查询结果
				XmlReaderTextBox.Text = ExecuteXmlReaderMySqlCommand().ToString();
			}
		}

		#region Web Form Designer generated code
		override protected void OnInit(EventArgs e)
		{
			//
			// CODEGEN: This call is required by the ASP.NET Web Form Designer.
			//
			InitializeComponent();
			base.OnInit(e);
		}
		
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{    
			this.Load += new System.EventHandler(this.Page_Load);

		}
		#endregion


		private object ExecuteScalarMySqlCommand()
		{
			String cmdText = "SELECT Staff_Name from Staff";
			SqlConnection myConnection = new SqlConnection(SQLCONNECTIONSTRING);
			SqlCommand myCommand = new SqlCommand(cmdText,myConnection);

			myConnection.Open();
			object scalarobject = myCommand.ExecuteScalar();
			myConnection.Close();		
	
			return(scalarobject);
		}

		private void ExecuteNonQueryMySqlCommand(String newName)
		{
			String cmdText = "UPDATE Staff Set Staff_Name='" + newName + "' WHERE Staff_ID = 1";
			SqlConnection myConnection = new SqlConnection(SQLCONNECTIONSTRING);
			SqlCommand myCommand = new SqlCommand(cmdText,myConnection);

			myConnection.Open();
			myCommand.ExecuteNonQuery();
			myConnection.Close();	
		}

		private String ExecuteXmlReaderMySqlCommand()
		{
			String cmdText = "SELECT Staff_Name from Staff For XML AUTO";
			SqlConnection myConnection = new SqlConnection(SQLCONNECTIONSTRING);
			SqlCommand myCommand = new SqlCommand(cmdText,myConnection);

			///重数据库获取XML片断
			myConnection.Open();
			XmlReader xmlReader = myCommand.ExecuteXmlReader();				

			///读取XML片断中的数据
			String xmlString = "";
			while(xmlReader.Read())
			{
				xmlString += xmlReader.ReadOuterXml() + "\n";
			}

			///关闭读取器和数据库的链接（次序不能颠倒）
			xmlReader.Close();
			myConnection.Close();
			return(xmlString);		
		}
	}
}