vb中调用sql数据库数据的登陆界面

1、vb中调用sql数据库数据的登陆界面 悬赏分：100 - 解决时间：2009-11-17 20:27 我的通用模块代码：Public conn As New ADODB.ConnectionPublic rs As New ADODB.RecordsetPublic addflag As BooleanPublic Sub clocn()On Error Resume NextIf conn.State <> adStateClosed Then conn.CloseSet conn = NothingEnd SubPublic fMainForm As frmMain Publi

2、c UserName As StringPublic Function ConnectString() As String 'returns a DB ConnectStringPublic Function ExecuteSQL(ByVal SQL As String, MsgString As String) As ADODB.Recordset 'executes SQL and returns Recordset Dim cnn As ADODB.Connection Dim rst As ADODB.Recordset Dim sTokens() As String

3、On Error GoTo ExecuteSQL_Error sTokens = Split(SQL) Set cnn = New ADODB.Connection cnn.Open ConnectString '连接数据库 If InStr("INSERT,DELETE,UPDATE", UCase$(sTokens(0) Then '如果在输入的sql语句中出现insert delete update 那么执行sql代码 cnn.Execute SQL MsgString = sTokens(0) & " query successfu

4、l" Else Set rst = New ADODB.Recordset rst.Open Trim$(SQL), cnn, adOpenKeyset, adLockOptimistic '执行查询代码（和上面的功能差不多，区别就是，上面的是执行数据库的更新，包括删除 增加 更新，而这里是查询） 'rst.MoveLast记录集移动到下一条记录 'get RecordCount得到数据库条目总数 Set ExecuteSQL = rst执行数据库查询 MsgString = "查询到" & rst.RecordCount &

5、; " 条记录 " '显示查询到的记录数 End IfExecuteSQL_Exit: Set rst = Nothing Set cnn = Nothing'以上为关闭记录集和数据库连接对象Exit Function ExecuteSQL_Error: MsgString = "查询错误: " & Err.Description Resume ExecuteSQL_ExitEnd FunctionPublic Function Testtxt(txt As String) As Boolean If Trim(txt) = &q

6、uot;" Then Testtxt = False Else Testtxt = True End IfEnd Function'判断txt是否为空，并且将testtxt设置为真或者假 Public Sub clors()On Error Resume NextIf rs.State <> adStateClosed Then rs.CloneSet rs = NothingEnd Sub登陆界面的确定按钮代码：Private Sub Command1_Click() Dim dl As New ADODB.Recordset Dim strmsg As Str

7、ing Dim txtSQL As String txtSQL = "select uid from dl where UID='" & Trim(yhm.Text) & "'" Set dl = ExecuteSQL(txtSQL, strmsg) If dl.BOF = True Then MsgBox " 用户名错误！", vbExclamation + vbOKOnly, "警告" yhm.SetFocus yhm.SelStart = 0 yhm.SelLength = L

8、en(yhm.Text) Exit Sub End If UserName = dl.Fields(0) txtSQL = "select UID from dl where PWD='" & Trim(mm.Text) & "'" Set dl = ExecuteSQL(txtSQL, strmsg) If dl.EOF = True Then MsgBox " 密码错误！", vbExclamation + vbOKOnly, "警告" mm.SetFocus mm.SelStart = 0 mm.SelLength = Len(mm.Text) Exit Sub End If OK = True zjm.Show Unload MeEnd Sub现在运行起来的错误是代码“3704”，麻烦说明错误，能帮忙注释最好希望可以留下QQ方便我请教 提问者： RZ雪儿 - 三级最佳答案dl是nothing还是有值？错误代码“3704”是表示“对象已关闭，不允许操作”。你的ExecuteSQL函数中有ExecuteSQL_Error:、ExecuteSQL_Exit:当你查询成功后你并没有主动退出函数