圖書館管理系統正文稿畢業論文-資料下載頁

　　

【正文】 g, ByVal myDBGrd As DataGrid) If = Then () End If Fill(sqlstr) = (0).DefaultView () End Sub Public Sub BindDBGrd(ByVal sqlstr As String, ByVal myDBGrd As DataGrid, ByVal SortExp As Object) If = Then () End If Fill(sqlstr) Dim dv As DataView = (0).DefaultView = SortExp = dv () End Sub Private Sub BindDBGrid() Dim sqlstr As String = select * from BookInfo,LendInfo where = and IsBack=0 and UserID=39。 + + 39。 BindDBGrd(sqlstr, ListDGrid) End Sub Public Function ExecReaderSql(ByVal sqlstr As String) As SqlDataReader If = Then () End If myCmd = New SqlCommand(sqlstr, myConn) Dim reader As SqlDataReader reader = () Return reader End Function Private Function GetBookID() As String Dim sqlstr As String = select BookID from BookInfo where BarCode=39。 + + 39。 Dim BookID As String = Dim myreader As SqlDataReader = ExecReaderSql(sqlstr) If Then BookID = myreader(BookID) End If () Return BookID End Function Public Function GetCurNum(ByVal UserID As String) As Integer Dim sqlstr As String = select count(*) as Num from LendInfo where UserID=39。 + UserID + 39。 and IsBack=0 Dim myreader As SqlDataReader = ExecReaderSql(sqlstr) Dim num As Integer = 0 If Then num = myreader(Num) End If () Return num End Function Public Function GetRowsNum(ByVal sqlstr As String) As Integer If = Then () End If Fill(sqlstr) () Return (0). End Function Public Function GetBookState(ByVal BookID As String) As Integer Dim sqlstr As String = select * from BookInfo where BookState=1 and BookID= + BookID If GetRowsNum(sqlstr) = 0 Then Return 2 End If sqlstr = select * from LendInfo where IsBack=0 and BookID = + BookID If GetRowsNum(sqlstr) 0 Then Return 1 End If sqlstr = select * from BookingInfo where BookID= + BookID If GetRowsNum(sqlstr) 0 Then Return 0 End If Return 1 End Function Public Function GetBookDate(ByVal UserID As String) As Integer Dim sqlstr As String = select BookDate from UserInfo where UserID=39。 + UserID + 39。 Dim myreader As SqlDataReader = ExecReaderSql(sqlstr) Dim num As Integer = 0 If Then num = myreader(BookDate) End If () Return num End Function Public Function LendBook(ByVal UserID As String, ByVal BookID As String) As Boolean Dim datenum As Integer = GetBookDate(UserID) Dim nowdate As Date = Dim ReturnDate As Date = (datenum) Dim sqlstr As String = insert into LendInfo(BookID,UserID,LendDate,ReturnDate,IsBack)values( sqlstr += 39。 + BookID + 39。 sqlstr += ,39。 + UserID + 39。 sqlstr += ,39。 + + 39。 sqlstr += ,39。 + + 39。 sqlstr += ,0) ExecNonSql(sqlstr) Return True End Function Public Function GetMax(ByVal UserID As String) As Integer Dim sqlstr As String = select BookNum from Users where UserID=39。 + UserID + 39。 Dim myreader As SqlDataReader = ExecReaderSql(sqlstr) Dim num As Integer = 0 If Then num = myreader(BookNum) End If () Return num End Function Private Sub Button1_Click(ByVal sender As , ByVal e As ) Handles Dim str As String = Dim BookID As String = GetBookID() If GetCurNum() = GetMax() Then (scriptjavascript:alert(39。借書數已滿?。?！39。)。/script) Return End If Dim state As Integer = GetBookState(BookID) If state = 1 Then LendBook(, BookID) Else Select Case state Case 2 : (scriptjavascript:alert(39。此書不在流通狀態或此書不存在！??！39。)。/script) Case 1 : (scriptjavascript:alert(39。此書不在書架上?。?！39。)。/script) Case 0 : (scriptjavascript:alert(39。此書已經有人預約！！！39。)。/script) End Select End If BindDBGrid() End SubEnd Class七、 總結，雖然不是很熟練，但是還是知道不少，對SQL中數據庫中基本操作也應用了不少，相信這次訓練是受益