cmarjoys.vb

代码：是由本人自主开发完成的

Public Class CMarjoys
    Public MarjoyID As Integer      '专业编号
    Public MarjoyName As String     '专业名称
    Public DepartmentID As Integer  '院系编号

    Public Sub Initials()           '初始化实例
        MarjoyID = 0
        MarjoyName = ""
        DepartmentID = 0
    End Sub

    Public Sub Equal(ByVal tmpmar As CMarjoys)      '给实例赋新值
        MarjoyID = tmpmar.MarjoyID
        MarjoyName = tmpmar.MarjoyName
        DepartmentID = tmpmar.DepartmentID
    End Sub
    Public Sub GetMarInfo(ByVal tmpmarname As String, ByVal tmpdepid As Integer)
        Dim sqlstr As String
        sqlstr = "select * from Marjoys where 专业名称='" & tmpmarname & "' AND " & _
                 " 院系编号=" & tmpdepid.ToString
        Dim dbset As DataSet
        dbset = GetDataFromDB(sqlstr)
        If Not dbset Is Nothing Then
            MarjoyID = dbset.Tables(0).Rows(0).Item("专业编号")
            MarjoyName = dbset.Tables(0).Rows(0).Item("专业名称")
            DepartmentID = dbset.Tables(0).Rows(0).Item("院系编号")
        Else
            Initials()
        End If
    End Sub

    Public Function IsInDB(ByVal tmpmarname As String, ByVal tmpdepid As Integer) As Boolean
        Dim sqlstr As String
        sqlstr = "SELECT * FROM Marjoys WHERE 专业名称='" & tmpmarname & "' AND 院系编号=" & _
                tmpdepid.ToString
        Dim dbset As DataSet
        dbset = GetDataFromDB(sqlstr)
        If Not (dbset Is Nothing) Then
            Return True
        Else
            Return False
        End If
    End Function
    Public Function HaveStudents(ByVal tmpmarid As Integer) As Boolean
        Dim sqlstr As String
        sqlstr = "SELECT * FROM Students WHERE 专业编号=" & tmpmarid.ToString
        Dim dbset As DataSet
        dbset = GetDataFromDB(sqlstr)
        If Not dbset Is Nothing Then
            Return True
        Else
            Return False
        End If
    End Function
    Public Function DeleteDB() As Boolean
        Dim sqlstr As String
        sqlstr = "DELETE FROM Marjoys WHERE 专业编号=" & MarjoyID.ToString
        If UpdateDataBase(sqlstr) Then
            Initials()
            Return True
        Else
            Return False
        End If
    End Function
    Public Function ModifyDB() As Boolean
        Dim sqlstr As String
        sqlstr = "UPDATE Marjoys SET 专业名称='" & MakeStr(MarjoyName) & "'" & _
                 " WHERE 专业编号=" & MarjoyID.ToString
        If UpdateDataBase(sqlstr) Then
            Return True
        Else
            Initials()
            Return False
        End If
    End Function
    Public Function InsertDB() As Boolean
        Dim sqlstr As String
        sqlstr = "INSERT INTO Marjoys(专业编号,专业名称,院系编号)" & _
                 " VALUES(" & MarjoyID.ToString & ",'" & MakeStr(MarjoyName) & "'," & _
                 DepartmentID.ToString & ")"
        If UpdateDataBase(sqlstr) Then
            Return True
        Else
            Initials()
            Return False
        End If
    End Function
    Public Function GetNewID() As Integer
        Dim i As Integer
        i = 1
        Dim sqlstr As String
        Dim dset As DataSet
        Dim drow As DataRow
        sqlstr = "SELECT * FROM  Marjoys ORDER BY 专业编号"
        dset = GetDataFromDB(sqlstr)
        If Not dset Is Nothing Then
            For Each drow In dset.Tables(0).Rows
                If i = drow.Item("专业编号") Then
                    i = i + 1
                Else
                    Return i
                End If
            Next
        End If
        Return i
    End Function
End Class