VB连接数据库有关问题-请求高手解答

VB连接数据库问题---急,请求高手解答
代码一,登录窗体


Public OK As Boolean '登录成功

Private Sub cmdCancel_Click() '“取消”按钮
  OK = False '登录失败标记
  Me.Hide '隐藏当前窗体
End Sub

Private Sub cmdOK_Click() '“确定”按钮
  Dim j As Single, NameKey As String, PasswordKey As String
  Dim strUserName As String, strPassword As String
  Static iTry As Integer '重试次数
  Dim rs As New ADODB.Recordset
   
  strUserName = txtUserName.Text '获取用户名
  strPassword = txtPWD.Text '获取用户密码
   
  If strUserName = "" Then '若用户名为空
  MsgBox "请输入用户名", vbOKOnly + vbCritical, "警告" '显示提示信息
  txtUserName.SetFocus '设置输入焦点
  Exit Sub '退出过程
  End If
  If strPassword = "" Then '若密码为空
  MsgBox "请输入密码", vbOKOnly + vbCritical, "警告" '显示提示信息
  txtPWD.SetFocus '设置输入焦点
  Exit Sub '退出过程
  End If
   
  strUserName = MakeStr(strUserName) '处理非法字符
  strPassword = MakeStr(strPassword)
   
  strSQL = "SELECT * FROM Users WHERE use_name='" & strUserName & "'" '查询用户名
  Set rs = QueryExt(strSQL) '读取指定用户名的资料
  If Not rs.EOF Then '若记录集不为空
  If rs("user_password") = strPassword Then '若密码相同
  OK = True '登记成功
  UserName = strUserName '保存用户名到全局变量
  Right = rs("user_remark") '保存用户权限
  Unload Me '卸载当前窗体
  Exit Sub '退出当前过程
  End If
  End If
  MsgBox "用户名或密码错误!", vbOKOnly + vbCritical, "警告" '错误登录提示
  txtUserName = "" '清空用户名
  txtPWD = "" '清空密码
  txtUserName.SetFocus '设置输入焦点
  iTry = iTry + 1 '累加重试次数
  If iTry >= 3 Then '重试次数超限
  MsgBox "非法用户,系统将关闭!", vbOKOnly + vbCritical, "警告" '提示关闭
  DBapi_Disconnect '断开数据库连接
  End '结束程序
  Else '未超过重试次数限制
  Exit Sub '退出过程
  End If
End Sub

Private Sub Form_Load()

End Sub



代码二:通用模块


Public fMainForm As frmMain
Private IsConnect As Boolean ' 标记数据库是否连接=
Private Connect_Num As Integer ' 标记执行Connect()函数后,访问数据库的次数

Private cnn As ADODB.Connection '连接数据库的Connection对象
Private rs As ADODB.Recordset '保存结果集的Recordset对象

Public strSQL As String '保存执行SQL语句的字符串
Public Conn As String '连接字符串
Public UserName As String '操作员名称
Public Right As Integer '操作员权限
Sub Main()
  Dim flogin As New frmLogin
  Conn = "Provider=SQLOLEDB.1;Password=11;User ID=pp;Initial Catalog=network;Data Source=PP-VISTA;"

  '数据库连接字符串
   
  flogin.Show vbModal '显示登录窗体
  If Not flogin.OK Then '若登录失败
  End '退出应用程序
  End If
   
  Unload flogin '卸载登录窗体
   
  frmSplash.Show '显示Splash窗体
  frmSplash.Refresh '刷新Splash窗体
  Set fMainForm = New frmMain '生成主窗体
  Load fMainForm '装载主窗体
  Unload frmSplash '卸载Splash窗体
   
  fMainForm.Show '显示主窗体
End Sub
Private Sub Connect() '连接数据库
  If IsConnect = True Then '如果连接标记为真,则返回。否则会出错
  Exit Sub
  End If
' Conn = "data source=.;initial catalog=student;user id=pp;password=11;"

   
  On Error GoTo DbOpenErr
  Set cnn = New ADODB.Connection '关键New用于创建新对象cnn