Call showMsg("學號和課程編號不能為空！", 1)
        cobSno.SetFocus
        Exit Sub
    End If
    
    isOk = MsgBox(vbCrLf & "您確定要刪除" & lbSname.Caption & "的選課信息么?", vbOKCancel + vbQuestion, "確認操作")
    
    If isOk = vbOK Then
    
        '刪除學生選課信息
        SQL = "delete from jc_sc where sno='" & cobSno.Text & "' and cno='" & cobCno.Text & "' "
        On Error GoTo CanNotDel
        cnn.Execute (SQL)
    
    End If
    
    Call Data_Display
CanNotDel:
    Call showMsg("無法刪除！", 0)
End Sub

Private Sub cmdExit_Click()
    Unload Me
    
End Sub



Private Sub cmdSave_Click()
        
     'On Error Resume Next
    strCno = Trim(cobCno.Text)
    strSno = Trim(cobSno.Text)
    strGrade = Trim(TxtGrade.Text)
    

    '檢查是否存在該課程數據
    If strCno = "" Or strCno = "" Then
         Call showMsg("課程編號和課程名稱不能為空！", 1)
         
        cobCno.SetFocus
        Exit Sub
    End If
        
    SQL = "select cno from jc_sc where cno='" & strCno & "'"
    Set rs = cnn.Execute(SQL)
    
    If rs.BOF And rs.EOF Then
            SQL = "insert into jc_sc(cno,sno,grade) "
            SQL = SQL & "values('" & strCno & "','" & strSno & "','" & strGrade & "') "
            cnn.Execute (SQL)
            Call showMsg("添加　選課信息 成功", 1)
        Else
            SQL = "update jc_sc set cno='" & strCno & "',sno='" & strSno & "',grade='" & strGrade & "' where cno='" & strCno & "' and sno='" & strSno & "'"
            cnn.Execute (SQL)
            Call showMsg("修改　選課信息 成功", 1)
    End If
    
    Call Data_Display
End Sub


Private Sub cobCno_Click()
   
    Dim tmpCname As String
    
    If cobCno.Text <> "" Then
    
    
    SQL = "select cname from jc_c where  cno='" & cobCno.Text & "' "
    Set rs = cnn.Execute(SQL)
    
        If (rs.BOF) Or (rs.EOF) Then
        
             Call showMsg("沒有找到任何記錄 ！", 1)
           
        Else
                '顯示所選記錄
                tmpCname = rs("cname")
        End If
    
     lbCname.Caption = "　課程名稱：" & tmpCname
     strCname = tmpCname
     
     
    End If
End Sub




Private Sub cobFind_Click()
     TxtKeyword.Enabled = True
End Sub

Private Sub Form_Activate()
    lbGrade.Caption = "注意：如果添加課程，請在成績處輸入 0 "
    cobFind.AddItem "學號", 0
    cobFind.AddItem "課程編號", 1
    
    Call Clear

End Sub

Private Sub TxtGrade_GotFocus()
    Dim isAdd As Integer
    If cobSno.Text <> "" And cobCno.Text <> "" Then
    
    SQL = "select grade from jc_sc where sno='" & cobSno.Text & "' and cno='" & cobCno.Text & "' "
    Set rs = cnn.Execute(SQL)
    
        If (rs.BOF) Or (rs.EOF) Then
            isAdd = MsgBox("沒有找到 " & strSname & " 所選擇的課程　" & strCname & "  的記錄，該同學目前還沒有選擇該課程。" & vbCrLf & "　請填寫成績并單擊 '添加/修改' 或 取消。", vbInformation + vbOKCancel, "提示")
            If isAdd = vbOK Then
                TxtGrade.Text = ""
            End If
            
           
        Else
                '顯示所選記錄
                TxtGrade.Text = rs("grade")
            
        End If
    
    End If
End Sub

Private Sub cobSno_Click()
       
    Dim tmpSname As String
    
    If cobSno.Text <> "" Then
    
    
    SQL = "select sname from jc_s where  sno='" & cobSno.Text & "' "
    On Error Resume Next
    Set rs = cnn.Execute(SQL)
    
        If (rs.BOF) Or (rs.EOF) Then
             Call showMsg("沒有找到任何記錄 ！", 1)
           
        Else
                '顯示所選記錄
                tmpSname = rs("sname")
        End If

     lbSname.Caption = "　學生姓名：" & tmpSname
     strSname = tmpSname
     
    End If
End Sub
Function getRecordsNums(ByVal TmpSql As String) As String
    Dim rs As ADODB.Recordset
    On Error Resume Next
    Set rs = cnn.Execute(TmpSql)
     lbScounts.Caption = "當前共" & rs("scnums") & "個選課信息"
     getRecordsNums = lbScounts.Caption
End Function
Private Sub getAllRecords()
  
    'SQL = "select count(sno) as scnums from jc_sc"
    'getRecordsNums SQL
    
    
     '把記錄和數據顯示控件綁定
    SQL = "select jc_s.sno,jc_s.sname,jc_c.cno,jc_c.cname,jc_sc.grade from jc_s,jc_c,jc_sc where jc_sc.sno=jc_s.sno and jc_sc.cno=jc_c.cno order by jc_sc.sno asc "
    'SQL = "select * from jc_sc "
    On Error Resume Next
    Set rs = cnn.Execute(SQL)
    Call Data_Display
    
End Sub

Private Sub getSc()
    SQL = "select distinct sno,distinct cno,grade from jc_sc "
    On Error Resume Next
    Set rs = cnn.Execute(SQL)
    '取得所有記錄
                Do While Not rs.EOF
                   cobSno.AddItem rs("sno")
                   cobCno.AddItem rs("cno")
                   cobGrade.AddItem rs("grade")
                    
                 rs.MoveNext
                Loop
End Sub

Private Sub Form_Load()
   Dim strErr As String
    
   If cnn.State = 0 Then
  
        On Error Resume Next
        cnn.Open connStr
       
   End If

   
    
    Call Clear
    Call getSc
    'Call getAllRecords
    
    Exit Sub
errNotable:
       strErr = "沒有找到相應數據，請確認所選擇的數據源指向的是MS SQL Server數據庫" & _
         vbCrLf & "并且數據庫中已經存在選課信息表。" & _
         vbCrLf & "您可以選擇初始化重新設置數據表。" & vbCrLf
    Call showMsg(strErr, 0)
    
End Sub
Private Sub Form_Resize()
     
    With Me
    
        Frame1.Left = (.ScaleWidth - Frame1.Width) / 2
        Frame1.Top = (.ScaleHeight - Frame1.Height) / 2
        
    End With
    
End Sub


Private Sub Form_Unload(Cancel As Integer)
    
    mdiFrm.stb.SimpleText = "就緒"
    Unload Me
End Sub
Private Sub MSFG_Clear()

    With MSFlexGrid1
        .Cols = 0
        .Rows = 0
    End With
    
End Sub

Private Sub Data_Display()

   
    Dim i As Integer

    '清空表
    Call MSFG_Clear
    With MSFlexGrid1
        On Error Resume Next
        If (rs.BOF) Or (rs.EOF) Then
            Call showMsg("沒有相關記錄！", 1)
            
             .Cols = 0
            .Rows = 0
            ' FrameScView.Visible = False
        Else
            .Cols = 5
            .Rows = 1
            'FrameScView.Visible = True
        
            '得到每一個列的列名
           ' For i = 0 To 4
           '     .TextMatrix(0, i) = rs.Fields(i).Name
           ' Next i
            
            .TextMatrix(0, 0) = "學號"
            .TextMatrix(0, 1) = "姓名"
            .TextMatrix(0, 2) = "課程編號"
            .TextMatrix(0, 3) = "課程名稱"
            .TextMatrix(0, 4) = "成績"
            
            .ColWidth(0) = 1000
            .ColWidth(1) = 1500
            .ColWidth(2) = 1000
            .ColWidth(3) = 1500
            .ColWidth(4) = 1000
            
            
            On Error GoTo rsErr
            
            Do While Not rs.EOF
                .Rows = .Rows + 1
                '顯示一條記錄
                For i = 0 To 4
                .TextMatrix(MSFlexGrid1.Rows - 1, i) = Trim(rs.Fields(i))
                Next i
                '移動游標到下一條記錄
                rs.MoveNext
            Loop
            
        End If
    End With
    
  Exit Sub
rsErr:
     Call showMsg(" ", 0)
     
End Sub


Private Sub MSFlexGrid1_Click()
    gRow = MSFlexGrid1.Row
    With MSFlexGrid1
    
        '得到一條記錄
        On Error GoTo exitThis
       ' TxtXH.Text = .TextMatrix(MSFlexGrid1.Rows - 1, 0)
       '如果為零，則說明所選擇的是第一行標題
        Call Clear
        If gRow <> 0 Then
            cobSno.Text = .TextMatrix(gRow, 0)
            lbSname.Caption = .TextMatrix(gRow, 1)
            cobCno.Text = .TextMatrix(gRow, 2)
            lbCname.Caption = .TextMatrix(gRow, 3)
            TxtGrade.Text = .TextMatrix(gRow, 4)
        End If
        
    End With
    
exitThis:
    
End Sub

Private Sub MSFlexGrid1_RowColChange()
   Call MSFlexGrid1_Click
End Sub