course.cls

VB类实现学生信息管理系统

VERSION 1.0 CLASS
BEGIN
  MultiUse = -1  'True
  Persistable = 0  'NotPersistable
  DataBindingBehavior = 0  'vbNone
  DataSourceBehavior  = 0  'vbNone
  MTSTransactionMode  = 0  'NotAnMTSObject
END
Attribute VB_Name = "course"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = True
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Option Explicit
Public course_no As Integer
Public course_name As String
Public course_type As String
Public course_des As String
Public State As Integer
Public oper_flag As String
Public Function valid() As Boolean
 valid = True
 
 If Not isnumber(course_no) Then
 valid = False
 End If
 
End Function

Public Sub query()
  Dim SQLstmt As String    '存放SQL语句的字符串
  Dim msg_error As String
  Dim tmp_res As ADODB.Recordset
  
  If db.db_state > 0 Then
  
    SQLstmt = "select * FROM course_info " '执行SQL语句"
    Set tmp_res = db.ExecuteSQL(SQLstmt, msg_error)
    
    Me.State = 2 '没有课程存在
     
    If InStr(msg_error, "query_ok") > 0 Then 'have record
       While (tmp_res.EOF = False)
            If Trim(tmp_res.Fields("course_no")) = Me.course_no Then
              Me.State = 1 '有用户存在
              Me.course_no = Trim(tmp_res.Fields("course_no"))
              Me.course_name = Trim(tmp_res.Fields("course_name"))
              Me.course_type = Trim(tmp_res.Fields("course_type"))
              Me.course_des = Trim(tmp_res.Fields("course_des"))
              Exit Sub
            Else
                tmp_res.MoveNext
            End If
       Wend
     Else
     End If
     
    
   
 End If
 
     Set tmp_res = Nothing
End Sub

Public Sub insert()
Dim SQLstmt As String    '存放SQL语句的字符串
Dim msg_error As String


If db.db_state > 0 Then '数据库是否打开
      Call query
       If Me.State = 2 Then 'unexisted,add it to database
          
          SQLstmt = "Insert Into course_info  Values(" & Me.course_no & ",'" & Me.course_name & "','" & Me.course_type & "','" & Me.course_des & "')"
          Call db.ExecuteSQL(SQLstmt, msg_error)
          
          If InStr(msg_error, "insert_ok") > 0 Then
             oper_flag = "insert_ok"
          Else
             oper_flag = "insert_error"
          End If
          
       End If
End If
 
  
End Sub

Public Sub delete()
Dim SQLstmt As String    '存放SQL语句的字符串
Dim msg_error As String
 
  If db.db_state > 0 Then
  
     SQLstmt = "DELETE FROM course_info  WHERE course_no=  " + CStr(Me.course_no)  '执行SQL语句
  
     Call db.ExecuteSQL(SQLstmt, msg_error)
    
     If InStr(msg_error, "delete_ok") > 0 Then
        Me.oper_flag = "delete ok"
     Else
        Me.oper_flag = "delete error"
     End If
    
  
  End If
End Sub
Public Sub update()

End Sub