module1.bas

学生信息管理系统（需要 SQL Server数据库支持）登录界面系统

Attribute VB_Name = "Module1"
Option Explicit
'判断登陆是否成功
Public OK As Boolean
Public UserName As String
Public fMainForm As New frmMain


'传递参数SQL传递查询语句,MsgString传递查询信息
'自身以一个数据集对象的形式返回

Public Function ExecuteSQL(ByVal SQL As String, MsgString As String) _
    As ADODB.Recordset
'定义连接

    Dim cnn As ADODB.Connection

'定义结果集

    Dim rst As ADODB.Recordset
'定义字符串

    Dim sTokens() As String
'异常处理

    On Err GoTo ExecuteSQL_Error
'用函数split产生一个包含各个子串的数组

    sTokens = Split(SQL)
'创立连接

    Set cnn = New ADODB.Connection
'打开连接

    cnn.Open ConnectString
'判断字符串是否含有指定内容

    If InStr("INSERT,UPDATE,DELET", UCase$(sTokens(0))) Then
'执行查询语句

        cnn.Execute SQL
'返回查询信息

        MsgString = sTokens(0) & "query successful"

    Else
'创建数据集对象
    
        Set rst = New ADODB.Recordset
'返回查询结果
'
      rst.Open Trim(SQL), cnn, adOpenKeyset, adLockOptimistic
        
'        rst.Open Trim$(SQL), cnn, adOpenKeyset, adLockOptimistic
   ' rst.MoveLast get recordcount
'返回结果集对象

        Set ExecuteSQL = rst
        MsgString = "查询到" & rst.RecordCount & "条记录"

    End If

ExecuteSQL_Exit:
'清空数据集对象

    Set rst = Nothing
'中断连接

    Set cnn = Nothing
    Exit Function
'错误类型判断

ExecuteSQL_Error:
     MsgString = "查询错误" & Err.Description
     Resume ExecuteSQL_Exit
 
End Function



Public Function ConnectString() As String
'返回一个数据库连接
   

    ConnectString = "FileDSN=mycon.dsn;UID=sa;PWD=;initial catalog=stumag"
'    ConnectString = "provider=sqloledb;data source=.;user id=sa;initial catalog=stumag"
    
  
End Function

Public Function Testtxt(txt As String) As Boolean
'判断输入是否为空

If Trim(txt) = "" Then
    Testtxt = False
Else
    Testtxt = True
End If
End Function

Sub Main()
Dim fLogin As New frmLogin
'显示登陆窗体
fLogin.Show vbModal

fLogin.Show vbModal
'判断是否是授权用户
If Not fLogin.OK Then
    End
End If
Unload fLogin

'判断是将进入系统
Set fMainForm = New frmMain
fMainForm.Show
    
     
End Sub