cancelreserve.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 CancelReserve


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

    Dim callDate As Date


    Dim rsNoStr As String = ""
    Dim rsNoArray As Array


    Sub cancle()

        setCallDate()

        setInfo()
        delete()

        MsgBox("seccess!")
        
    End Sub

    Sub setInfo()

        ' Try
      
        myConnection.Open()

        myCommand = New OleDbCommand("select * from ReserveBook where Status='called'and [CallDate]=#" & callDate & "#", myConnection)

        MsgBox("calldate" & callDate)
        myReader = myCommand.ExecuteReader()

        While myReader.Read
            rsNoStr += myReader("ReserveNo").ToString + ","
        End While

        If rsNoStr = "" Then
            MsgBox("rsNoStr is empty")
        End If
        'Catch ex As Exception
        ' MsgBox(ex.ToString)
        'End Try

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


    End Sub
    Sub delete()

        ' myConnection.Open()

        Dim i As Integer

        rsNoArray = rsNoStr.Split(",")

        '  myConnection.Open()

        For i = 0 To rsNoArray.Length - 2

            Dim temprsNo As Integer
            temprsNo = Integer.Parse(rsNoArray(i))


            myCommand = New OleDbCommand("Delete From ReserveBook where reserveNo=" & temprsNo, myConnection)

            myCommand.ExecuteNonQuery()

        Next

        ' myConnection.Close()
        ' myCommand.Dispose()

    End Sub

    Sub setCallDate()

        Dim st As String
        st = DateTime.Today.AddDays(-3).ToShortDateString

        callDate = Date.Parse(st)
        MsgBox("" & callDate.ToShortDateString)

    End Sub
End Class