mydatarelation.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.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.Configuration;

namespace Example_8_3
{
	/// <summary>
	/// Summary description for MyDataRelation.
	/// </summary>
	public class MyDataRelation : System.Web.UI.Page
	{
		protected System.Web.UI.WebControls.Label SQLLabel;
		protected System.Web.UI.WebControls.DataGrid myDataGrid;
		private readonly string SQLCONNECTIONSTRING = ConfigurationSettings.AppSettings["SQLCONNECTIONSTRING"].ToString();

		private void Page_Load(object sender, System.EventArgs e)
		{
			if(!Page.IsPostBack)
			{
				///创建DataRelation对象
				CreateDataRelation();
			}
		}

		private void CreateDataRelation()
		{
			///从数据库中获取表记录
			String cmdText = "SELECT Staff.*,Role.* FROM Staff "
				+ "INNER JOIN StaffRole ON Staff.Staff_ID = StaffRole.Staff_ID "
				+ "INNER JOIN Role ON Role.Role_ID = StaffRole.Role_ID";		
			SqlConnection myConnection = new SqlConnection(SQLCONNECTIONSTRING);
			SqlCommand myCommand = new SqlCommand(cmdText,myConnection);

			///执行数据库查询
			myConnection.Open();
			SqlDataReader dr = myCommand.ExecuteReader();

			///创建DataTableStaff对象
			DataTable dataTableStaff = new DataTable();
			///添加新的数据列
			dataTableStaff.Columns.Add("StaffID",typeof(int));
			dataTableStaff.Columns.Add("StaffName",typeof(string));
			dataTableStaff.Columns.Add("RealName",typeof(string));
			dataTableStaff.Columns.Add("Birthday",typeof(DateTime));
			dataTableStaff.Columns.Add("Email",typeof(string));

			///创建DataTableStaff对象
			DataTable dataTableRole = new DataTable();
			///添加新的数据列
			dataTableRole.Columns.Add("RoleID",typeof(int));
			dataTableRole.Columns.Add("RoleName",typeof(string));

			///创建DataTableStaff对象
			DataTable dataTableStaffRole = new DataTable();
			///添加新的数据列
			dataTableStaffRole.Columns.Add("Staff_Staff_ID",typeof(int));
			dataTableStaffRole.Columns.Add("Role_Role_ID",typeof(int));		

			///添加表的关系，即使用DataRelation对象
			DataRelation relationStaff = new DataRelation("Staff_Staff",
				dataTableStaff.Columns["StaffID"],
				dataTableStaffRole.Columns["Staff_Staff_ID"]);

			///添加表的关系，即使用DataRelation对象
			DataRelation relationRole = new DataRelation("Role_Role",
				dataTableRole.Columns["RoleID"],
				dataTableStaffRole.Columns["Role_Role_ID"]);

			///创建新的数据集
			DataSet dataSet = new DataSet();
			dataSet.Tables.Add(dataTableRole);
			dataSet.Tables.Add(dataTableStaff);
			dataSet.Tables.Add(dataTableStaffRole);

			dataSet.Relations.Add(relationRole);
			dataSet.Relations.Add(relationStaff);

			while(dr.Read())
			{
				///添加dataTableStaff表新的数据行
				DataRow rowStaff = dataTableStaff.NewRow();
				rowStaff["StaffID"]   = dr["Staff_ID"].ToString();
				rowStaff["StaffName"] = dr["Staff_Name"].ToString();
				rowStaff["RealName"]  = dr["RealName"].ToString();
				rowStaff["Birthday"]  = dr["Birthday"].ToString();
				rowStaff["Email"]     = dr["Email"].ToString();
				dataTableStaff.Rows.Add(rowStaff);

				///添加dataTableRole表新的数据行
				DataRow rowRole = dataTableRole.NewRow();
                rowRole["RoleID"]    = dr["Role_ID"].ToString();
				rowRole["RoleName"]  = dr["Role_Name"].ToString();
				dataTableRole.Rows.Add(rowRole);

				///添加dataTableStaffRole表新的数据行
				DataRow rowStaffRole = dataTableStaffRole.NewRow();
				rowStaffRole["Staff_Staff_ID"]   = dr["Staff_ID"].ToString();
				rowStaffRole["Role_Role_ID"]    = dr["Role_ID"].ToString();
				dataTableStaffRole.Rows.Add(rowStaffRole);
			}
			dr.Close();
			myConnection.Close();	
	
			SQLLabel.Text = cmdText;
			myDataGrid.DataSource = dataSet.Tables[1];
			myDataGrid.DataBind();
		}

		#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
	}
}