database.bas

小小图书管理系统是功能完善,已经可以实用于小型单位或科室的图书管理.系统界面美观,操作方便,代码带有详尽的注释,相信大家一定会喜欢

Attribute VB_Name = "Database"
 '公共变量声明
Option Explicit
Public constr As String           '数据库连接信息字符串
Public privilege As Integer       '用户权限
Public rst As ADODB.Recordset     '数据库内的记录,定义两个记录集对象
Public rst1 As ADODB.Recordset
Public con As ADODB.Connection    '数据库连接对象
Public tablename As String
Type userdata                     '定义用户信息类型，包括用户名，密码和对应的权限
   user_id As String
   pwd As String
   right As Integer
End Type

 '定义数据库连接的函数
 Public Sub connect_db()
 constr = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + App.Path + "\book_manage_db.mdb" + ";Persist Security Info=False" '数据库引擎+路径
 Set con = New ADODB.Connection     '新建一个数据库连接
 con.CursorLocation = adUseClient   '用于客户端（ADOR）Recordset对象，游标库属性必须为adUseClient
 con.ConnectionString = constr      '连接信息
 con.Open
End Sub

 '创建数据库连接并进行数据访问的函数
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 + "\book_manage_db.mdb" + ";Persist Security Info=False"
  con.Open sqlstr
  str = "select * from " & table_name & ""  '执行SQL查询
  rst.Open str, con, adOpenDynamic, adLockOptimistic
  rst.Requery
End Function

 '进行用户功能管理函数
Public Sub check_privage(rightlevel As Integer)
Dim right As Integer
 right = rightlevel
Select Case right
        Case 1:                         '普通用户，只能查询图书信息和借阅信息
        
         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.xpcmdbutton11.Enabled = False
         
         Form1.Show
         Unload frmLogin
        Case 2:                        '借书管理员，还可以借书和打印凭证
        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.xpcmdbutton11.Enabled = True
         
         Form1.Show
         Unload frmLogin
        Case 3:                         '还书管理员，可以还书
       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.xpcmdbutton11.Enabled = False
         
         Form1.Show
         Unload frmLogin
        Case 4:                          '超级用户
         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.xpcmdbutton11.Enabled = True
         Form1.Show
         Unload frmLogin
      End Select
End Sub