databusiness.vb

电子商务买书的网站

Public Class DataBusiness           'DataBusiness是自己定义的类的名称

    '该函数用来添加新书
    Public Function InsertBook(ByVal strBookName As String, ByVal strBookAuthor As String, ByVal sglBookPrice As Single, ByVal intBookNum As Integer, ByVal bytPicture() As Byte, ByVal strBookIntro As String, ByVal strBookIndex As String, ByVal intKindId As Integer) As Boolean
        '下面定义一个错误对象，以便捕获错误。
        Dim Exp As Exception
        Try
            '下面设置有关变量值
            Dim dtmSubmitDate As Date = Now()

            '下面建立DataBooks对象，然后调用方法添加数据
            Dim dbks As New DataBooks
            dbks.InsertBook(strBookName, strBookAuthor, sglBookPrice, intBookNum, bytPicture, strBookIntro, strBookIndex, intKindId, dtmSubmitDate)

            Return (True)
        Catch Exp
            '如果发生错误
            Return (False)
        End Try
    End Function

    '该函数用来更新一本书的信息
    Public Function UpdateBook(ByVal intBookId As Integer, ByVal strBookName As String, ByVal strBookAuthor As String, ByVal sglBookPrice As Single, ByVal intBookNum As Integer, ByVal bytPicture() As Byte, ByVal strBookIntro As String, ByVal strBookIndex As String, ByVal intKindId As Integer) As Boolean
        '下面定义一个错误对象，以便捕获错误。
        Dim Exp As Exception
        Try
            '下面设置有关变量值
            Dim dtmSubmitDate As Date = Now()

            '下面建立DataBooks对象，然后调用方法添加数据
            Dim dbks As New DataBooks
            dbks.UpdateBook(intBookId, strBookName, strBookAuthor, sglBookPrice, intBookNum, bytPicture, strBookIntro, strBookIndex, intKindId, dtmSubmitDate)

            Return (True)
        Catch Exp
            '如果发生错误
            Return (False)
        End Try
    End Function


    '该函数用来删除书
    Public Function DeleteBook(ByVal intBookId As Integer) As Boolean
        '下面定义一个错误对象，以便捕获错误。
        Dim Exp As Exception
        Try
            '下面建立DataBooks对象，然后调用方法删除数据
            Dim dbks As New DataBooks
            dbks.DeleteBook(intBookId)

            Return (True)
        Catch exp
            Return (False)
        End Try
    End Function

    '下面查询记录，返回所有指定条件的书籍
    Public Function GetBook(ByVal intKindId As Integer, ByVal strKeyword As String, ByVal strkeyField As String) As DataView
        '下面返回DataView对象
        Dim dbks As New DataBooks
        Dim dv As DataView = dbks.GetBook()           '返回所有书籍

        '下面设置筛选条件，首先设置类别条件
        Dim strFilter As String
        strFilter = "BookId>0"              '这个条件其实没有用，主要是为了后面书写其他条件时方便
        If intKindId > 0 Then
            strFilter &= " And KindId=" & intKindId
        End If

        '然后根据查询关键字设置条件
        If strKeyword <> "" And strKeyword <> "全部" Then
            Dim arryKeyword() As String
            Dim I As Integer
            arryKeyword = Split(strKeyword, " ")         '按空格拆分多个关键词
            '根据不同的字段进行不同的搜索方式
            If strKeyField = "BookName" Then
                For I = 0 To arryKeyword.Length - 1
                    strFilter &= " And " & strkeyField & " Like '%" & arryKeyword(I) & "%'" '注意And前留一个空格
                Next
            ElseIf strkeyField = "BookAuthor" Then
                For I = 0 To arryKeyword.Length - 1
                    strFilter &= " And " & strkeyField & " = '" & arryKeyword(I) & "'"  '注意And前留一个空格
                Next
            End If
        End If
        dv.RowFilter = strFilter               '设置筛选条件


        '下面根据排序字段设置排序效果，为了简单，直接按SubmitDate降序排列
        dv.Sort = "SubmitDate Desc"
        '最后返回筛选后的DataView
        Return (dv)
    End Function

    '下面查询记录，返回所有书。注意和上面的函数名称相同，但参数不同
    Public Function GetBook()
        '下面返回DataView对象
        Dim dbks As New DataBooks
        Dim dv As DataView = dbks.GetBook()           '返回所有书籍
        dv.Sort = "SubmitDate Desc"
        Return (dv)
    End Function

    '下面查询记录，返回一本书
    Public Function GetOneBook(ByVal intBookId As Integer) As DataView
        Dim dbks As New DataBooks
        Dim dv As DataView = dbks.GetOneBook(intBookId)
        Return (dv)
    End Function

    '下面查询记录，返回某类书销量前10名
    Public Function GetTop10(ByVal intKindId As Integer) As DataView
        Dim dbks As New DataBooks
        Dim dv As DataView = dbks.GetTop10(intKindId)
        Return (dv)
    End Function


    '该函数返回所有类别
    Public Function GetKind() As DataView
        Dim dks As New DataKinds
        Dim dv As DataView = dks.GetKind()
        dv.Sort = "KindId"               '设置排序条件
        Return (dv)
    End Function

    '删除类别
    Public Sub DeleteKind(ByVal intKindId As Integer)
        Dim dks As New DataKinds
        dks.DeleteKind(intKindId)
    End Sub

    '更新类别信息
    Public Sub UpdateKind(ByVal intKindId As Integer, ByVal strKindName As String)
        Dim dks As New DataKinds
        dks.UpdateKind(intKindId, strKindName)
    End Sub

    '添加类别
    Public Sub InsertKind(ByVal strKindName As String)
        Dim dks As New DataKinds
        dks.InsertKind(strKindName)
    End Sub

    '该函数用于返回所有订单
    Public Function GetOrder()
        '下面返回DataView对象
        Dim dos As New DataOrders
        Dim dv As DataView = dos.GetOrder()           '返回所有书籍
        dv.Sort = "Consign,SubmitDate Desc"          '按是否已经发货和提交日期排序
        Return (dv)
    End Function

    '删除订单
    Public Sub DeleteOrder(ByVal intOrderId As Integer)
        Dim dos As New DataOrders
        dos.DeleteOrder(intOrderId)
    End Sub

    '更新订单
    Public Sub UpdateOrder(ByVal intOrderId As Integer)
        Dim dos As New DataOrders
        dos.UpdateOrder(intOrderId, Now())
    End Sub

End Class