于sql的连接问题

[sdgqx]

Dim uid, pwd As String
Dim cn As ADODB.Connection
uid = txtUser.Text
pwd = txtPwd.Text
If uid <> "" Or pwd <> "" Then
cn.ConnectionString = "Provider=MSDASQL.1;Persist Security Info=False;" & "User ID=" & uid & ";password=" & pwd & ";Data Source=(local);Initial Catalog=telphone"
cn.Open
MsgBox "登錄成功", vbOKOnly
ConnectString = cn.ConnectionString
cn.Close
Unload Me
Else
MsgBox "用戶名或密碼不能為空!", vbInformation, "錯誤"
txtUser.SetFocus
End If

为什么老出错

[LCAAA]

DatabaseName = databasenametxt
cn.ConnectionString = "provider=" & providercob & ";server=" & servernametxt & ";uid=" & uidtxt & ";pwd=" & userpwd & ";database=" & DatabaseName
cn.CursorLocation = adUseClient
cn.Open
Dim msg As String
Set snp = Nothing
s = " SELECT 授权.*"
s = s & " FROM 授权 "
s = s & " where 授权.编号='" & Trim$(nametxt.Text) + "' and (管理类别=" & IIf(app_type = "系统维护", "'系统维护'", "'" & app_type & "管理'") & ")"
snp.Open s, cn
If snp.EOF Then
Chk = 1
Else
If Not IsNull(snp("口令")) Then
If txtpwd.Text <> snp("口令") Then
Chk = 2
Else
If IsNull(snp("WorkAt")) Then
Chk = 0
Else
If snp("WorkAt") <> ComputerName Then
Chk = 3
Else
Chk = 0
End If
End If
End If
Else
If txtpwd.Text <> "" Then
Chk = 2
Else
If IsNull(snp("WorkAt")) Then
Chk = 0
Else
If snp("WorkAt") <> ComputerName Then
Chk = 3
Else
Chk = 0
End If
End If
End If
End If
End If
If Chk = 0 Then
DoEvents
'进入
LogSuccess
welfrm.Visible = True
welfrm.Refresh
Me.MousePointer = 0
Unload Me
Exit Sub
ElseIf Chk = 3 Then
msg = Chr$(13) & "该用户已在" & snp("WorkAt") & "上工作" & Chr$(13) & "不准再次登录！"
MsgBox msg, 48
Else
counter = counter - 1
If counter = 0 Then
msg = Chr$(13) & "你不是合法用户！" & Chr$(13) & "对不起，再见！"
MsgBox msg, 48
cn.Close
Set snp = Nothing
Set cn = Nothing
End
ElseIf counter = 1 Then
msg = Chr$(13) & "这是最后一次．请仔细！"
Else
msg = Chr$(13) & "别急，想好．请再试一次"
End If
If Chk = 1 Then
MsgBox "无此编号∶" & nametxt.Text & msg, 48
ElseIf Chk = 2 Then
MsgBox "错误口令" & Chr$(13) & msg, 48
End If
txtpwd.Text = ""
End If

[sunrise10]

出什么错？

[sdgqx]

就是cnn.connectstring的属性出错
说对象变量没有设置

[jornet]

在之前添加一句: set cn =new adodb.connection
因为楼主只申明了变量没有实列化

[lihonggen0]

Dim cn As ADODB.Connection

[lihonggen0]

象这样：
工程--->引用--->Microsoft ActiveX Data Object 2.x（版本号）

Dim CN As New ADODB.Connection '定义数据库的连接
Dim Rs As New ADODB.Recordset
CN.ConnectionString = "Provider=sqloledb;Data Source=pmserver;Initial Catalog=northwind;User Id=sa;Password=sa;"
CN.Open
Rs.CursorLocation = adUseClient
Rs.Open "select * from employees", CN, adOpenDynamic, adLockOptimistic