conn_mdb.vb

图书管理系统VB.NET版本

Imports System.Data
Imports System.Data.OleDb
Module conn_mdb

    Declare Function HtmlHelp Lib "hhctrl.ocx" Alias "HtmlHelpA" (ByVal hwndCaller As Integer, _
              ByVal pszFile As String, ByVal uCommand As Integer, ByVal dwData As Integer) As Integer    '调用帮助文件
    Public ConAccess As OleDb.OleDbConnection    '连接Mdb数据库
    Public OleDbCom As OleDbCommand              '检索命令
    Public DatRead As OleDb.OleDbDataReader      '检索结果的数据流
    Public OleSuccess As Boolean                '检索是否成功
    Public all As Boolean                       '是否全查询
    Public Field(12) As String                   '浏览字段
    Public ds As DataSet   '保存在内存缓冲区的数据记录集合
    Public da As OleDb.OleDbDataAdapter   '数据源与DataSet之间数据交换的桥梁
    Public PageNo As Int16    '打印页号
    Public PageCount As Int16   '打印页数
    Public CountItem As String   '打印表头
    Public type_book As String    '表的名称分类
    Public count As Int32       '表中记录总数
    Public list As New list    '检索结果显示窗口
    Public jieshu As Boolean    'false为初值，true为检索回显
    Public shuid As String   '借书还书地ID编号
    Public UserName As String     '用户名
    Public Psw As String         '密码
    Public dlSuccess As Boolean = False  '登录正确
    Public Sub OpenMdb()
        ConAccess = New OleDb.OleDbConnection
        ConAccess.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Persist Security Info=false;Data Source=" & Application.StartupPath & "\book.mdb"
        ConAccess.Open()
    End Sub

    Public Sub ReadMdb(ByVal str As String)
        OleDbCom = New OleDb.OleDbCommand      '构造命令
        OleDbCom.Connection = ConAccess
        OleDbCom.CommandType = CommandType.Text
        OleDbCom.CommandText = str
        OleSuccess = True
        Try
            DatRead = OleDbCom.ExecuteReader()
        Catch ex As Exception
            MessageBox.Show("错误信息：" & ex.Message.ToString, "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Information)
            OleSuccess = False
        End Try
    End Sub
    Function CountMdb(ByVal str As String)
        OleDbCom = New OleDb.OleDbCommand      '构造命令
        OleDbCom.Connection = ConAccess
        OleDbCom.CommandType = CommandType.Text
        OleDbCom.CommandText = "SELECT COUNT(*) FROM " & str
        Try
            CountMdb = OleDbCom.ExecuteScalar()
        Catch ex As Exception
            MessageBox.Show("错误信息：" & ex.Message.ToString, "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Information)
        End Try
    End Function

    Public Sub WriteMdb(ByVal str As String)
        OleDbCom = New OleDb.OleDbCommand      '构造命令
        OleDbCom.Connection = ConAccess
        OleDbCom.CommandType = CommandType.Text
        OleDbCom.CommandText = str
        OleSuccess = True
        Try
            OleDbCom.ExecuteScalar()
        Catch ex As Exception
            MessageBox.Show("错误信息：" & ex.Message.ToString, "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Information)
            OleSuccess = False
        End Try
    End Sub

    Public Function optchange(ByVal str As String) As String
        Select Case str
            Case "等于"
                optchange = "="
            Case "大于"
                optchange = ">"
            Case "小于"
                optchange = "<"
            Case "大于等于"
                optchange = ">="
            Case "小于等于"
                optchange = "<="
            Case "不等于"
                optchange = "<>"
            Case "包含"
                optchange = "LIKE%%"
            Case "左包含"
                optchange = "LIKE%"
            Case "右包含"
                optchange = "LIKE"
        End Select
    End Function

    Public Function FieldMapping(ByVal str As String) As String
        Select Case str
            Case "ID编号"
                FieldMapping = "ID"
            Case "分类号"
                FieldMapping = "FLH"
            Case "书名"
                FieldMapping = "SM"
            Case "主编"
                FieldMapping = "ZB"
            Case "出版社"
                FieldMapping = "CBS"
            Case "单价"
                FieldMapping = "DJ"
            Case "版次"
                FieldMapping = "BC"
            Case "装订"
                FieldMapping = "ZD"
            Case "借阅者"
                FieldMapping = "JYZ"
            Case "借书日期"
                FieldMapping = "JSRQ"
            Case "还书日期"
                FieldMapping = "HSRQ"

        End Select
    End Function
End Module