borrow.cls

来自「vb与access数据库的操作实例」· CLS 代码 · 共 108 行

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
  Persistable = 0  'NotPersistable
  DataBindingBehavior = 0  'vbNone
  DataSourceBehavior  = 0  'vbNone
  MTSTransactionMode  = 0  'NotAnMTSObject
END
Attribute VB_Name = "Borrow"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
'1 BorrowNo 文本 20 借阅编号，设定为系统当前时间，具体到毫秒
'2 Cardno  文本 20 借阅证编号
'4 BorrowDate 日期\时间 借阅日期

Public BorrowNo As String
Public Cardno As String
Public BorrowDate As String

Public Sub Init()
  BorrowNo = ""
  Cardno = ""
  BorrowDate = Date
End Sub

'删除借阅记录，同时删除借阅明细。只有所有借阅图书都归还，方可删除
Public Sub Delete(ByVal TmpBNo As String)
  SqlStmt = "DELETE FROM Borrow WHERE BorrowNo='" + Trim(TmpBNo) + "'"
  SQLExt (SqlStmt)
  '删除明细
  MyBorrowList.DeleteByBNo (TmpBNo)
End Sub

Public Function GetInfo(ByVal TmpBNo As String) As Boolean
  If Trim(TmpBNo) = "" Then
    GetInfo = False
    Init
    Exit Function
  End If
  
  BorrowNo = TmpBNo
  Dim rs As New ADODB.Recordset
  
  SqlStmt = "SELECT * FROM Borrow WHERE BorrowNo='" + Trim(TmpBNo) + "'"
  Set rs = QueryExt(SqlStmt)
  If rs.EOF Then
    GetInfo = False
    Init
    Exit Function
  Else
    If IsNull(rs.Fields(1)) Then
      Cardno = ""
    Else
      Cardno = Trim(rs.Fields(1))
    End If
    If IsNull(rs.Fields(2)) Then
      BorrowDate = ""
    Else
      BorrowDate = Trim(rs.Fields(2))
    End If
  End If
  GetInfo = True
End Function
'取得表中最大的借阅编号
Public Function GetMaxNo() As String
  Dim rs As New ADODB.Recordset
  
  SqlStmt = "SELECT MAX(Mid(BorrowNo,3)) FROM Borrow"
  Set rs = QueryExt(SqlStmt)
  If Not rs.EOF Then
    GetMaxNo = rs.Fields(0)
  Else
    GetMaxNo = "001"
  End If
End Function
Public Function In_DB(ByVal TmpBNo As String) As Boolean
  If Trim(TmpBNo) = "" Then
    In_DB = False
    Init
    Exit Function
  End If
  
  Dim rs As New ADODB.Recordset
  
  SqlStmt = "SELECT * FROM Borrow WHERE BorrowNo='" + Trim(TmpBNo) + "'"
  Set rs = QueryExt(SqlStmt)
  If Not rs.EOF Then
    In_DB = True
  Else
    In_DB = False
  End If
End Function

Public Sub Insert()
  SqlStmt = "INSERT INTO Borrow(BorrowNo,CardNo,BorrowDate) Values('" + Trim(BorrowNo) + "','" _
     + Trim(Cardno) + "','" + Trim(BorrowDate) + "')"
  SQLExt (SqlStmt)
End Sub

Public Sub Update(ByVal TmpBNo As String)
  SqlStmt = "Update Borrow Set Cardno='" + Trim(Cardno) + "'" _
          + " WHERE BorrowNo='" + Trim(TmpBNo) + "'"
  SQLExt (SqlStmt)
End Sub