booktype.cls

图书管理系统,采用VB+SQL,含最好的代码和数据库备份.

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
  Persistable = 0  'NotPersistable
  DataBindingBehavior = 0  'vbNone
  DataSourceBehavior  = 0  'vbNone
  MTSTransactionMode  = 0  'NotAnMTSObject
END
Attribute VB_Name = "BookType"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Public TypeId As Long
Public TypeName As String
Public UpperId As Long

Public Sub Init()
  TypeId = -1
  TypeName = ""
  UpperId = -1
End Sub

'删除BookType
Public Sub Delete(ByVal TmpId As Long)
  SqlStmt = "DELETE FROM BookType WHERE TypeId=" + Trim(Str(TmpId))
  SQLExt (SqlStmt)
End Sub

Public Sub GetInfo(TmpId As Long)
  TypeId = TmpId
  Dim rs As New ADODB.Recordset '定义结果集对象
  '使用SELECT语句读取指定类型数据
  SqlStmt = "SELECT * FROM BookType WHERE TypeId=" + Trim(Str(TmpId))
  Set rs = QueryExt(SqlStmt)
  If Not rs.EOF Then
    TypeName = TrimStr(rs.Fields(1))  '类型名称
    UpperId = Val(rs.Fields(2))       '上级编号
  Else
    Init
  End If
End Sub

Public Function GetName(ByVal TmpId As Long) As String
  Dim rs As New ADODB.Recordset
  
  SqlStmt = "SELECT TypeName FROM BookType WHERE TypeId=" _
          + Trim(Str(TmpId))
  Set rs = QueryExt(SqlStmt)
  If Not rs.EOF Then
    GetName = TrimStr(rs.Fields(0))
  Else
    GetName = ""
  End If
End Function

Public Function GetUpperName(ByVal TmpId As Long) As String
  Dim rs As New ADODB.Recordset
  
  SqlStmt = "SELECT u.TypeName FROM BookType a,BookType u WHERE a.UpperId=u.TypeId AND a.TypeId=" _
          + Trim(Str(TmpId))
  Set rs = QueryExt(SqlStmt)
  If Not rs.EOF Then
    GetUpperName = TrimStr(rs.Fields(0))
  Else
    GetUpperName = ""
  End If
End Function

Public Function GetUpperId(ByVal TmpId As Long) As Integer
  Dim rs As New ADODB.Recordset
  
  SqlStmt = "SELECT UpperId FROM BookType WHERE TypeId=" _
          + Trim(Str(TmpId))
  Set rs = QueryExt(SqlStmt)
  If Not rs.EOF Then
    GetUpperId = Val(rs.Fields(0))
  Else
    GetUpperId = -1
  End If
End Function

Public Function HaveBook(ByVal TmpId As Long) As Boolean
  Dim rs As New ADODB.Recordset
  '设置要执行的SQL语句
  SqlStmt = "SELECT TypeId FROM BookInfo WHERE TypeId=" + Trim(TmpId)
  '执行SQL语句
  Set rs = QueryExt(SqlStmt)
  '如果没有满足条件查询结果
  If rs.EOF Then
    HaveBook = False
  Else
    HaveBook = True
  End If
End Function

Public Function HaveSon(ByVal TmpUpperId As Long) As Boolean
  Dim rs As New ADODB.Recordset
  '设置要执行的SQL语句
  SqlStmt = "SELECT TypeId FROM BookType WHERE UpperId=" _
          + Trim(Str(TmpUpperId))
  '执行SQL语句
  Set rs = QueryExt(SqlStmt)
  '如果没有满足条件查询结果
  If rs.EOF Then
    HaveSon = False
  Else
    HaveSon = True
  End If
End Function

Public Function In_DB(ByVal TypeName As String) As Boolean
  Dim rs As New ADODB.Recordset
  
  SqlStmt = "SELECT TypeId FROM BookType WHERE TypeName='" _
          + Trim(TypeName) + "'"
  Set rs = QueryExt(SqlStmt)
  If Not rs.EOF Then
    In_DB = True
  Else
    In_DB = False
  End If
End Function

Public Function Insert() As Long
  Dim rs As New ADODB.Recordset  '定义结果集对象
  '因为TypeId的类型为自动编号,所以在插入数据时没有考虑TypeId字段
  SqlStmt = "INSERT INTO BookType(TypeName,UpperId) VALUES('" + Trim(TypeName) _
          + "'," + Trim(Str(UpperId)) + ")"
  '执行INSERT语句
  SQLExt (SqlStmt)
  '设置SELECT语句,读取表BookType中TypeId字段的最大值
  SqlStmt = "SELECT MAX(TypeId) FROM BookType"
  '读取记录集到rs对象
  Set rs = QueryExt(SqlStmt)
  '返回最大编号值
  If Not rs.EOF Then
    Insert = rs.Fields(0)
  Else
    Insert = 1
  End If
End Function

Public Sub Load_by_Upper(ByVal UpperId As Integer)
  Dim rs As New ADODB.Recordset
  Dim i As Long
  '对数组进行初始化
  Erase Arr_BookType
  ReDim Arr_BookType(0)
  Erase Arr_TypeId
  ReDim Arr_TypeId(0)
  '设置SQL语句
  SqlStmt = "SELECT TypeId, TypeName FROM BookType WHERE UpperId=" _
          + Trim(Str(UpperId)) + " ORDER BY TypeName"
  '执行SQL语句
  Set rs = QueryExt(SqlStmt)
  i = 0
  '依次把读取的数据赋值到数组中
  Do Until rs.EOF
    ReDim Preserve Arr_TypeId(i + 1)
    Arr_TypeId(i) = Val(rs.Fields(0))

    ReDim Preserve Arr_BookType(i + 1)
    Arr_BookType(i) = TrimStr(rs.Fields(1))
    rs.MoveNext

    i = i + 1
  Loop
End Sub

'更新数据
Public Sub Update(ByVal TmpId As Long)
  SqlStmt = "UPDATE BookType SET TypeName='" + Trim(TypeName) _
          + "' WHERE TypeId=" + Trim(Str(TmpId))
  SQLExt (SqlStmt)
End Sub