求大神指教数据库链接问题
用VS2005与SQL的数据库进行连接，编一个登陆窗口，，哪位大神给出具体点代码
[解决办法]

  <connectionStrings>
    <add name="ConnectionString" providerName="System.Data.SqlClient" connectionString="server=localhost\SQLEXPRESS;database=数据库名;uid=sa;pwd=12345"/>
  </connectionStrings>  



protected void btn_OK_Click(object sender, EventArgs e)
{

    AppUser user = AppSettingSRV.VerifyPassword(loginName, password);
    if (user == null)
    {
        AppUser loginUser = AppSettingSRV.GetAppUserByLoginName(loginName);
        this.LoginFail.InnerText = (loginUser == null ? "用不存在." : "密码错误.");
    }
    else
    {
        this.LoginFail.InnerText = "登录成功";
    }
    
}

public static AppUser GetAppUserByLoginName(string loginName)
{
    AppUserORM user = AppUserController.GetAppUserByLoginName(loginName);
    if (user == null)
    {
        return null;
    }
    return user.ConvertAppUserORMToEDM();
}

public static AppUserORM GetAppUserByLoginName(string loginName)
{
    string sql = "SELECT * FROM AppUser WHERE LoginName = @LoginName";
    SqlCommand command = new SqlCommand(sql);
    command.Parameters.Add("@LoginName", SqlDbType.NVarChar).Value = loginName;
    DataTable table = DBProvider.DefaultDBOperator.GetDataTable(command);
    if (table.Rows.Count == 0)
    {
        return null;
    }
    return table.Rows[0].ConvertToDBModel<AppUserORM>();
}

[解决办法]
呵呵，着急； 传送门DBhelp类，执行sql 存储过程 事务等,调用这个类里面的方法就行了