Option Explicit
Public constr As String           '數(shù)據(jù)庫連接信息
Public privilege As Integer       '用戶權(quán)限
Public rst As ADODB.Recordset     '數(shù)據(jù)庫內(nèi)的記錄
Public rst1 As ADODB.Recordset
Public con As ADODB.Connection
Public tablename As String
Type userdata                     '用戶信息，包括用戶名，密碼和對應(yīng)的權(quán)限
   user_id As String
   pwd As String
   right As Integer
End Type

Public Sub connect_db()
 constr = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + App.Path + "\data\ComputerBookmanage.mdb" + ";Persist Security Info=False" '數(shù)據(jù)庫引擎+路徑
 Set con = New ADODB.Connection     '新建一個(gè)數(shù)據(jù)庫連接
 con.CursorLocation = adUseClient   '用于客戶端（ADOR）Recordset對象，游標(biāo)庫屬性必須為adUseClient
 con.ConnectionString = constr      '連接信息
 con.Open
End Sub
Function open_connection(table_name As String)
Dim sqlstr As String
Dim str As String
  Set con = New ADODB.Connection
  Set rst = New ADODB.Recordset
  con.CursorLocation = adUseClient
  sqlstr = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + App.Path + "\data\ComputerBookmanage.mdb" + ";Persist Security Info=False"
  con.Open sqlstr
  str = "select * from " & table_name & ""  '執(zhí)行SQL查詢
  rst.Open str, con, adOpenDynamic, adLockOptimistic
  rst.Requery
End Function

Public Sub check_privage(rightlevel As Integer)
Dim right As Integer
 right = rightlevel
Select Case right
        Case 1:                         '普通用戶，只能查詢圖書信息和借閱信息
        
         Form1.xpcmdbutton1.Enabled = False
         Form1.xpcmdbutton2.Enabled = False
         
         Form1.xpcmdbutton3.Enabled = False
         Form1.xpcmdbutton4.Enabled = False
         Form1.xpcmdbutton5.Enabled = True
         Form1.xpcmdbutton6.Enabled = True
         Form1.xpcmdbutton7.Enabled = False
         
         Form1.xpcmdbutton8.Enabled = False
         Form1.Show
         Unload frmLogin
        Case 2:                        '借書管理員，還可以借書和打印憑證
        Form1.xpcmdbutton1.Enabled = True
         Form1.xpcmdbutton2.Enabled = False
         
         Form1.xpcmdbutton3.Enabled = False
         Form1.xpcmdbutton4.Enabled = False
         Form1.xpcmdbutton5.Enabled = True
         Form1.xpcmdbutton6.Enabled = True
         Form1.xpcmdbutton7.Enabled = True
         
         Form1.xpcmdbutton8.Enabled = False
        Form1.Show
         Unload frmLogin
        Case 3:                         '還書管理員，可以還書
       Form1.xpcmdbutton1.Enabled = False
         Form1.xpcmdbutton2.Enabled = True
         
         Form1.xpcmdbutton3.Enabled = False
         Form1.xpcmdbutton4.Enabled = False
         Form1.xpcmdbutton5.Enabled = True
         Form1.xpcmdbutton6.Enabled = True
         Form1.xpcmdbutton7.Enabled = True
         
         Form1.xpcmdbutton8.Enabled = False
         Form1.Show
         Unload frmLogin
        Case 4:                          '超級用戶
         Form1.xpcmdbutton1.Enabled = True
         Form1.xpcmdbutton2.Enabled = True
         
         Form1.xpcmdbutton3.Enabled = True
         Form1.xpcmdbutton4.Enabled = True
         Form1.xpcmdbutton5.Enabled = True
         Form1.xpcmdbutton6.Enabled = True
         Form1.xpcmdbutton7.Enabled = True
         
         Form1.xpcmdbutton8.Enabled = True
         Form1.Show
         Unload frmLogin
      End Select
End Sub