usercheck.cs

《C#数据库项目案例导航》一书的配套光盘

using System;
using System.Data;
using System.Data.SqlClient;
using Sale.DataLevel;

namespace Sale.BussinessRule
{
	
	// UserCheck类用于通过输入用户名和密码来返回用户类别。
	
	public class UserCheck
	{
		public static string UserSortCheck(string username,string userpassword)
		{			
			string txtSql;					
			string usersort="nobody";
			SqlConnection conn1=new SqlConnection(Sale.DataLevel.Login.Connection);
			//创建数据库连接   
			txtSql = "SELECT * FROM [User]";
			SqlCommand checkuser=new SqlCommand(txtSql,conn1);
			//创建SqlCommad
			try
			{
				conn1.Open();				
				SqlDataReader sqlreader=checkuser.ExecuteReader();
				while(sqlreader.Read())
				{	
					if((sqlreader[0].ToString().Trim()==username)&&(sqlreader[1].ToString().Trim()==userpassword))
					{						
						usersort=sqlreader[2].ToString().Trim();//返回用户类别						
						break;						
					}
				}		
			}
			catch(Exception e)
			{				
				Console.WriteLine(e.ToString());
			}						
			conn1.Close();				
			return usersort;
			
		}		
	}
}