Could not update database

[Ayavan]

i am just developing a library management system as one of my project. i using vb.net 2010 and the MS Access 2007 as back end. when i save some records into my database through my application it is correctly saved and i confirmed it through opening the relevant table in the database. but when i restart the application all the entered data were missing.. help me to solve this

[Alexpap]

Can you provide us with the functionality that fetches the data from your database?

[Mitja Bonca]

So this means 2 things:
- or you dont retreive the right data
- or you dont have the correctly.

Can we see some of your code that does these two things?

[Ayavan]

Imports System.Data
Imports System.Data.OleDb

Public Class Form4
    Public con As New OleDb.OleDbConnection
    Public ada1 As New OleDb.OleDbDataAdapter
    Public cmd1 As New OleDb.OleDbCommandBuilder
    Public dt1 As New DataTable
    Public row As DataRow
    Shared r As Integer
    Dim up As String
    Dim found As Boolean
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If TextBox1.Text = "" Then
            MsgBox("Book No Should be entered", MsgBoxStyle.Information, "SLMS")
        ElseIf TextBox2.Text = "" Then
            MsgBox("Book Name Should be entered", MsgBoxStyle.Information, "SLMS")
        ElseIf TextBox3.Text = "" Then
            MsgBox("Author Name Should be entered", MsgBoxStyle.Information, "SLMS")
        ElseIf TextBox4.Text = "" Then
            MsgBox("Publisher Name Should be entered", MsgBoxStyle.Information, "SLMS")
        ElseIf TextBox5.Text = "" Then
            MsgBox("Published Year Should be entered", MsgBoxStyle.Information, "SLMS")
        ElseIf ComboBox1.Text = "" Then
            MsgBox("Category Name Should be entered", MsgBoxStyle.Information, "SLMS")
        ElseIf TextBox8.Text = "" Then
            MsgBox("Quantity Should be entered", MsgBoxStyle.Information, "SLMS")

        Else

            Try

                ada1 = New OleDb.OleDbDataAdapter("UPDATE books1 SET BookNo='" & TextBox1.Text & "', BookName='" & TextBox2.Text & "', AuthorName='" & TextBox3.Text & "', PublisherName='" & TextBox4.Text & "', PublishedYear='" & TextBox5.Text & "', Price='" & Val(TextBox6.Text) & "', CategoryName='" & ComboBox1.Text & "', Quantity='" & Val(TextBox8.Text) & "', ISBNNumber='" & TextBox9.Text & "', ClassificationNo='" & TextBox10.Text & "' WHERE BookNo='" & TextBox1.Text & "'", con)

                cmd1 = New OleDb.OleDbCommandBuilder(ada1)
                ada1.Fill(dt1)
                MsgBox("Successfully Updated", , "Login")
            Catch ex As Exception
            End Try
        End If
        TextBox1.Text = ""
        TextBox2.Text = ""
        TextBox3.Text = ""
        TextBox4.Text = ""
        TextBox5.Text = ""
        TextBox6.Text = ""
        ComboBox1.Text = ""
        TextBox8.Text = ""
        TextBox9.Text = ""
        TextBox10.Text = ""


    End Sub

    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        'Update button
        Button1.Enabled = True
        Button2.Enabled = True

        If TextBox1.Text = "" Then
            MsgBox("Book No Should be entered", MsgBoxStyle.Information, "SLMS")
        Else
            Try
                up = TextBox1.Text

                found = False
                r = 0
                Do While (r < dt1.Rows.Count)
                    If (up = dt1.Rows(r)("BookNo")) Then

                        found = True
                        'bind
                        TextBox1.Text = dt1.Rows(r)("BookNo")
                        TextBox2.Text = dt1.Rows(r)("BookName")
                        TextBox3.Text = dt1.Rows(r)("AuthorName")
                        TextBox4.Text = dt1.Rows(r)("PublisherName")
                        TextBox5.Text = dt1.Rows(r)("PublishedYear")
                        TextBox6.Text = dt1.Rows(r)("Price")
                        ComboBox1.Text = dt1.Rows(r)("CategoryName")
                        TextBox8.Text = dt1.Rows(r)("Quantity")
                        TextBox9.Text = dt1.Rows(r)("ISBNNumber")
                        TextBox10.Text = dt1.Rows(r)("ClassificationNo")
                        Exit Do
                    End If
                    r = r + 1
                Loop
                If Not found Then
                    MsgBox("Book not found", , "SLMS")
                End If
            Catch ex As Exception
                MsgBox(ex.Message, , "SLMS")
            End Try
        End If
    End Sub

    Private Sub Form4_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Button1.Enabled = False
        Button2.Enabled = False
        Try
            con.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=libraryDB.accdb"
            con.Open()
            ada1 = New OleDb.OleDbDataAdapter("select * from books1", con)
            cmd1 = New OleDb.OleDbCommandBuilder(ada1)
            ada1.Fill(dt1)
        Catch ex As Exception
            MsgBox(ex.Message, , "Libraray")
        End Try
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Try
            If found = True Then
                dt1.Rows(r).Delete()
                ada1.Update(dt1)
                MsgBox("Successfully Deleted", , "SLMS")
            End If
            TextBox1.Text = ""
            TextBox2.Text = ""
            TextBox3.Text = ""
            TextBox4.Text = ""
            TextBox5.Text = ""
            TextBox6.Text = ""
            ComboBox1.Text = ""
            TextBox8.Text = ""
            TextBox9.Text = ""
            TextBox10.Text = ""
        Catch ex As Exception
            MsgBox(ex.Message)

        End Try
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Me.Close()
    End Sub
End Class

[Ayavan]

That is the full code i uded in the form which is used to modify or delete the details of the book. it works correctly and making the changes in the DB too but after few minutes Those records are missing from the database

[Mitja Bonca]

One thing to mention before even starting looking into this "mess" of the code.
Use parameterized query. Check URL="http://blog.divergencehosting.com/2009/04/09/using-parameters-parameterized-queries-database-interactions-cshar-vbnet/"][/UhereRL] what this means.
It basicly means that you dont specify textBoxes values directly in the query, but you add them in the command.

Next, it would be better to get all the data from DB into a dataTable, and then use dataBinding for each textBox. Check here what dataBinding is.
Take your time. Its not so easy task to do, especially if you didnt do it before.
If you have any issues with C# code there, use C# to VB converter.

Hope it helps,
bye