frm_addreader.vb

是关于图书管理系统的用vb.net 和access开发的

Imports System.Data.OleDb
Public Class frm_AddReader


    Dim myConnection As New OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0; Data source=D:\library.mdb")
    Dim myCommand As OleDbCommand
    Dim myReader As OleDbDataReader




    Private Sub okbt_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles okbt.Click
        If Trim(readerNotxt.Text) = "" Then
            displayMsg("User ID can not be empty")
            Exit Sub
        End If
        If Trim(nameTxt.Text) = "" Then
            displayMsg("User name can not be empty")
            Exit Sub
        End If
        If Trim(passwordtxt.Text) = "" Then
            displayMsg("User password can not be empty")
            Exit Sub
        End If

       

        If checkIfAreadyExists(readerNotxt.Text) = False Then
            displayMsg("User has already existed")
            Exit Sub
        Else
            addUser()
            displayMsg("add successful")
        End If
    End Sub

    Sub displayMsg(ByVal msg As String)

        MsgBox(msg, MsgBoxStyle.Information, "libarary management system")

    End Sub

    Function checkIfAreadyExists(ByVal id) As Boolean
        Dim temp As String
        temp = ""

        myConnection.Open()
        myCommand = New OleDbCommand("select * from SystemUsers where userID='" & id & "'", myConnection)
        myReader = myCommand.ExecuteReader()


        While myReader.Read
            temp = myReader.Read()
        End While

        myConnection.Close()
        myCommand.Dispose()
        myReader.Close()

        If temp <> id Then
            Return True
        Else
            Return False
        End If


    End Function

    Sub addUser()
        myConnection.Open()
        myCommand = New OleDbCommand("INSERT INTO ReaderDetails VALUES('" & _
       readerNotxt.Text & "','" & typecombo.SelectedText & "','" & passwordtxt.Text & "','" & _
        nametxt.Text & "','" & addresstxt.Text & "','" & phonetxt.Text & "','" & emailtxt.Text & _
        "','" & sexcombo.SelectedText & "')", myConnection)

        myCommand.ExecuteNonQuery()
        myConnection.Close()
        myCommand.Dispose()
    End Sub


    Private Sub userIdTxt_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles readerNotxt.TextChanged

    End Sub
End Class