【机房收费系统】上机

      上机是机房收费系统的三大难点之一，但是不要给自己的思想设限，说它很难很难，捋清思路逻辑，用到那几个表分析清楚，敲代码的时候会顺利很多。一定要画流程图，一定要画流程图，一定要画流程图（重要的事情说三遍）。它会是你搂逻辑的一大工具。

部分代码：

If Trim(txtcardno.Text) = "" Then
        MsgBox "卡号不能为空，请重新输入！", vbOKOnly + vbExclamation, "警告"
        txtcardno.SetFocus
        Exit Sub
    End If
    Rem：判断输入卡号是否为数字
    If Not IsNumeric(Trim(txtcardno)) Then
        MsgBox "卡号请输入数字!", vbOKOnly + vbExclamation, "警告"
        txtcardno.SetFocus
        txtcardno.Text = ""
        Exit Sub
    End If
txtsql = "select * from student_info where cardno='" & Trim(txtcardno.Text) & " '"
Set mrc = executeSQL(txtsql, msgtext)      'mrc用于student表的查询
        '判断卡号是否注册
     If mrc.EOF Then
        MsgBox "卡号没有被注册，请重新输入！", vbOKOnly + vbExclamation, "警告"
        txtcardno.SetFocus
        Exit Sub
     End If
txtsql = "select* from basicdata_info"
Set mrc1 = executeSQL(txtsql, msgtext)
        '判断该卡号余额是否足够
    If mrc.Fields(7) < mrc1.Fields(5) Then
        MsgBox "余额只有" & mrc.Fields(7) & "少于最小金额，请充值！", vbOKOnly + vbExclamation, "警告"
        txtcardno.Text = ""
        txtcardno.SetFocus
        Exit Sub
    End If
    '判断该卡号是否在上机
txtsql = "select * from online_info where cardno='" & txtcardno.Text & "'"
Set mrc2 = executeSQL(txtsql, msgtext)
    If (mrc2.EOF Or mrc2.BOF) = False Then      '若不为空
        MsgBox "该卡号正在上机！", vbOKOnly + vbExclamation, "警告"
        
        Rem：如果在上机从mrc2调取上机记录显示在text中
        txtType = Trim(mrc2.Fields(1))
        txTSTUDENTNO = Trim(mrc2.Fields(2))
        txtstudentname = Trim(mrc2.Fields(3))
        txtdepartment = Trim(mrc2.Fields(4))
        txtsex = Trim(mrc2.Fields(6))
        txtondate = Trim(Format(mrc2.Fields(6), "yyyy-mm-dd"))
        txtontime = Trim(Format(mrc2.Fields(7), "hh:mm:ss"))
        txtcash = Trim(mrc.Fields(7))
    Else
    Rem：如果没有上机，查询student中的记录
txtsql = "select * from online_info where cardno='" & txtcardno & "'"
Set mrc2 = executeSQL(txtsql, msgtext)
    Rem：将信息显示在text中
            txtType = Trim(mrc.Fields(14))
            txTSTUDENTNO = Trim(mrc.Fields(1))
            txtstudentname = Trim(mrc.Fields(2))
            txtdepartment = Trim(mrc.Fields(4))
            txtsex = Trim(mrc.Fields(3))
            txtondate = Trim(Format(Date, "yyyy-mm-dd"))
            txtontime = Trim(Format(Time, "hh:mm:ss"))
            txtcash = Trim(mrc.Fields(7))
        Rem：更新online
        mrc2.AddNew
        mrc2.Fields(0) = Trim(txTSTUDENTNO)
        mrc2.Fields(1) = Trim(txtType)
        mrc2.Fields(2) = Trim(txTSTUDENTNO)
        mrc2.Fields(3) = Trim(txtstudentname)
        mrc2.Fields(4) = Trim(txtdepartment)
        mrc2.Fields(5) = Trim(txtsex)
        mrc2.Fields(6) = (Format(txtondate))
        mrc2.Fields(7) = (Format(txtontime))
        mrc2.Fields(8) = Trim(VBA.Environ("computername"))
        mrc2.Fields(9) = Trim(Now)          '当前时间
        mrc2.Update
      
        Rem：向line中记录
         txtsql = "select * from line_info "
         Set mrc3 = executeSQL(txtsql, msgtext)
         mrc3.AddNew
         mrc3.Fields(1) = Trim(txtcardno)
         mrc3.Fields(2) = Trim(txTSTUDENTNO)
         mrc3.Fields(3) = Trim(txtstudentname)
         mrc3.Fields(4) = Trim(txtdepartment)
         mrc3.Fields(5) = Trim(txtsex)
         mrc3.Fields(6) = Trim(txtondate)
         mrc3.Fields(7) = Trim(txtontime)
         mrc3.Fields(12) = mrc.Fields(7)
         mrc3.Fields(13) = "正常上机"
         mrc3.Fields(14) = VBA.Environ("computername")
         mrc3.Update
         mrc3.Close
        
        Rem：显示上机成功
        MsgBox "上机成功！", vbOKOnly, "提示"

显示上机人数：

  Dim mrc0 As ADODB.Recordset
        txtsql = "select * from online_info "
       Set mrc0 = executeSQL(txtsql, msgtext)
        Label2.Caption = "当前上机人数：" & mrc0.RecordCount
        txtcardno.SetFocus
    End If