conntodb.vb

图书管理系统能过完成基本的功能

Imports System
Imports System.Data
Imports System.Drawing
Imports System.Data.OleDb

Module ConnToDB

    Public StartPath As String = Application.StartupPath & "\DBLibery.mdb"
    Public ConnStr As String = "Provider=Microsoft.Jet.OLEDB.4.0; "
    Public ConnectStr As String = ConnStr & "Data Source=" & StartPath
    Public DataAdapter As OleDbDataAdapter
    Public DataConnection As OleDbConnection
    Public DataSet As DataSet

    Public Function GetDataFromDB(ByVal sqlstr As String) As DataSet
        Try
            DataConnection = New OleDbConnection
            DataConnection.ConnectionString = ConnectStr
            DataAdapter = New OleDbDataAdapter(sqlstr, DataConnection)
            DataSet = New DataSet
            DataSet.Clear()
            DataAdapter.Fill(DataSet)
            DataConnection.Close()
        Catch
            MsgBox(Err.Description)
        End Try
        If DataSet.Tables(0).Rows.Count > 0 Then
            Return DataSet
        Else
            Return Nothing
        End If
    End Function

    Public Function UpdateDataBase(ByVal sqlstr As String) As Boolean
        Dim sqlconn As New OleDbConnection(ConnectStr)
        Try
            Dim cmdTable As OleDbCommand = New OleDbCommand(sqlstr, sqlconn)
            cmdTable.CommandType = CommandType.Text
            sqlconn.Open()
            cmdTable.ExecuteNonQuery()
            sqlconn.Close()
        Catch
            MessageBox.Show(Err.Description)
            Return False
        End Try
        Return True
    End Function

    Public Class Dictionary
        Public ISBN As String
        Public FineBase As Double
        Public FineMulti As Double
        Public FineFactor As Double
    End Class

    Public Structure OnceLends
        Public ReadStyle As String
        Public LendBooks As Integer
    End Structure

    Public Structure BorrowType
        Public Type As String
        Public Days As Integer
    End Structure

End Module