freeze.vb

是关于图书管理系统的用vb.net 和access开发的

Imports System.Data.OleDb
Public Class freeze

    Dim myConnection As New OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0; Data source=D:\library.mdb")
    Dim myCommand As OleDbCommand
    Dim myReader As OleDbDataReader



    Sub freeze()
      
        Dim readerNoArray As Array
        Dim i As Integer

        readerNoArray = getReaderNoStr.Split(",")

        myConnection.Open()

        For i = 0 To readerNoArray.Length - 1

            Dim tempReaderNo As String
            tempReaderNo = readerNoArray(i)


            myCommand = New OleDbCommand("Update ReaderDetails set Status= 'freeze' where ReaderNo='" & tempReaderNo & "'", myConnection)

            myCommand.ExecuteNonQuery()

        Next

        MsgBox("Today's Freeze has already been completed!")
        
        myConnection.Close()
        myCommand.Dispose()
   
    End Sub
    Function getReaderNoStr() As String

        Dim readerNoStr As String = ""

        dim 
        Try
            myConnection.Open()

            myCommand = New OleDbCommand("select * from RentBook where  Status='Nreturned'and  [DueDate]= #" & Date.Today & "#", myConnection)

            myReader = myCommand.ExecuteReader

            While myReader.Read
                readerNoStr += myReader("ReaderNo").ToString + ","
            End While

            myConnection.Close()
            myCommand.Dispose()
            myReader.Close()


        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try

        Return readerNoStr
    End Function
    Sub updateFine()

        Dim readerNoArray As Array
        Dim i As Integer

        readerNoArray = getReaderNoStr.Split(",")

        myConnection.Open()

        For i = 0 To readerNoArray.Length - 1

            Dim tempReaderNo As String
            tempReaderNo = readerNoArray(i)


            myCommand = New OleDbCommand("INSERT INTO Fine VALUES( " & _
         fineNo & ",'" & isbn & "','" & readerno & "','" & admNotxt.Text & "','" _
         & fineDate & "','" & totalFine & "','paid','Book lost')", myConnection)

            myCommand.ExecuteNonQuery()

        Next

        MsgBox("Today's Freeze has already been completed!")

        myConnection.Close()
        myCommand.Dispose()





        Dim fineDate As Date = Now

      
       



       

        MsgBox("The fine record is added successfully!")

    End Sub
End Class