VB6动态连接数据库模板

‘===========================================================================
‘用法：

‘1、在程序所在目录建立Setup.ini

‘2、在ini文件中添加如下信息：
‘[Setup Information]
‘Server = 服务器名
‘UserName = 用户名
‘Password = 密码
‘Data = 数据库

‘3、工程引用Microsoft Axtivex data objects 2.6 library

‘4、修改ini.bas中main中修改form.Show

‘5 、在需要连接数据库的窗体顶端加入以下代码:
‘    Option Explicit
‘    Dim Conn As New ADODB.Connection
‘    Dim Rs As New ADODB.Recordset

‘6、连接数据库：
‘Conn.Open "driver={SQL Server};server=" + Trim(Server) + ";uid=" + Trim(User) + ";pwd=" + Trim(Password) + ";database=" + Trim(Data) + ""
‘Rs.Open "select * from 表民", Conn, adOpenKeyset, adLockOptimistic

‘7、退出数据库连接:
‘        Rs.Close
‘        Conn.Close
‘        Set Rs = Nothing
‘        Set Conn = Nothing

‘===========================================================================


‘保存执行SQL语句的字符串
‘Public SqlStmt As String

‘声明写入ini文件的API函数
Public Declare Function WritePrivateProfileString Lib "kernel32" Alias "WritePrivateProfileStringA" (ByVal lpApplicationName As String, ByVal lpKeyName As String, ByVal lpString As Any, ByVal lpFilenchame As String) As Long
Public Declare Function WritePrivateProfileSection Lib "kernel32" Alias "WritePrivateProfileSectionA" (ByVal lpAppName As String, ByVal lpString As String, ByVal lpFilenchame As String) As Long

‘定义服务器参数常量
Public Server As String
Public User As String
Public Password As String
Public Data As String

‘程序进入点
Sub main()

  ‘从Setup.ini中读取服务器的名字
  Server = GetKey(App.Path + "\Setup.ini", "Server")
  User = GetKey(App.Path + "\Setup.ini", "User")
  Password = GetKey(App.Path + "\Setup.ini", "Password")
  Data = GetKey(App.Path + "\Setup.ini", "Data")
  ‘如果读取不成功，退出
  If Server = "" Then
  MsgBox "Setup.ini文件参数错误！", , "警告"
  End If
  
  ‘显示系统主界面
  Form1.Show

End Sub

‘判断文件是否存在
Function FileExist(Fname As String) As Boolean
  On Local Error Resume Next
  FileExist = (Dir(Fname) <> "")
End Function
‘读取ini文件的数据项值
Public Function GetKey(Tmp_File As String, Tmp_Key As String) As String
  Dim File As Long
  ‘分配文件句柄
  File = FreeFile
  
  ‘如果文件不存在则创建一个默认的Setup.ini文件
  If FileExist(Tmp_File) = False Then
    GetKey = ""
    Call WritePrivateProfileString("Setup Information", "Server", "", App.Path + "\Setup.ini")
    Call WritePrivateProfileString("Setup Information", "UserName ", " ", App.Path + "\Setup.ini")
    Call WritePrivateProfileString("Setup Information", "Password", " ", App.Path + "\Setup.ini")
    Call WritePrivateProfileString("Setup Information", "Data", " ", App.Path + "\Setup.ini")
    Exit Function
  End If
  
  ‘读取数据项值
  Open Tmp_File For Input As File
    Do While Not EOF(1)
      Line Input #File, buffer
      If Left(buffer, Len(Tmp_Key)) = Tmp_Key Then
        pos = InStr(buffer, "=")
        GetKey = Trim(Mid(buffer, pos + 1))
      End If
    Loop
  Close File
End Function