Visual Basic

access databse into datagridview

27-Apr-09 9:54

ROTFL - I know just what you mean

Christian Graus

Driven to the arms of OSX by Vista.

"I am new to programming world. I have been learning c# for about past four weeks. I am quite acquainted with the fundamentals of c#. Now I have to work on a project which converts given flat files to XML using the XML serialization method" - SK64 ( but the forums have stuff like this posted every day )

rajulama26-Apr-09 22:30

26-Apr-09 22:30

Hello everyone,
I just wonder what's wrong with my code. Actually I want to use openfiledialog to locate an access database file and then display it in datagridview. I used following connection string:

Dim sConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Extended Properties=;Data Source=" & fi.DirectoryName

and following to call the table

Dim objCmdSelect As New OleDbCommand("select * from table1" & fi.Name, objConn)

But I get the famous error: "the microsoft jet database engine cannot open the file. it is already opened exclusively by another user or you need permission to view its data."

But neither by database is open nor its password protected.

Please help me resolving this problem

Christian Graus26-Apr-09 22:45

26-Apr-09 22:45

I suggest you google for a tool which tells you what process has a file open. I know such a tool exists. It's plain the file is open, you need to work out why.

rajulama26-Apr-09 22:54

26-Apr-09 22:54

thanks for your suggestions but I think you misunderstood my problem. Following is complete code and its not working:

If OpenFileDialog1.ShowDialog(Me) = DialogResult.OK Then
               Dim fi As New FileInfo(OpenFileDialog1.FileName)
               Dim sConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Extended Properties=;Data Source=" & fi.DirectoryName
               Dim objConn As New OleDbConnection(sConnectionString)
               Dim objDataSet As DataSet = New DataSet()
               objConn.Open()
               Dim objCmdSelect As New OleDbCommand("select * from [Joint Restraint Assignments]" & fi.Name, objConn)
               Dim objAdapter1 As New OleDbDataAdapter
               objAdapter1.SelectCommand = objCmdSelect
               objAdapter1.Fill(objDataSet, "test")
               DataGridView1.DataSource = objDataSet.Tables(0).DefaultView
               objConn.Close()
           End If

I just wonder what's wrong with this code, in particular when i want to read access database file.

Christian Graus26-Apr-09 22:59

26-Apr-09 22:59

Ok, why do you need a fileinfo object ? I suspect that's what's locking your file. I did not misunderstand, your file is locked, if you like it or not.

rajulama26-Apr-09 23:02

26-Apr-09 23:02

thanks.
what can be an alternative to fileInfo?

Christian Graus26-Apr-09 23:07

26-Apr-09 23:07

you have the path already, use System.IO.Path.GetDirectoryName and Path.GetFileName to get the pieces of the file path that you seem to need.

rajulama26-Apr-09 23:10

26-Apr-09 23:10

sorry I didn't get it. Could you please give me an example?

Christian Graus26-Apr-09 23:12

26-Apr-09 23:12

In the System.IO namespace:

Path.GetDirectory("c:\documents\word.doc")

will return c:\documents

Path.GetFileName("c:\documents\word.doc")

will return word.doc.

The Path class is full of methods for manipulating and examining file paths

rajulama26-Apr-09 23:17

26-Apr-09 23:17

but my file location is not fixed. I want users to select the access database file and display a table from it into datagridview.

Christian Graus26-Apr-09 23:21

26-Apr-09 23:21

*sigh*

Dim fi As New FileInfo(OpenFileDialog1.FileName)
Dim sConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Extended Properties=;Data Source=" & fi.DirectoryName
Dim objConn As New OleDbConnection(sConnectionString)
Dim objDataSet As DataSet = New DataSet()
objConn.Open()
Dim objCmdSelect As New OleDbCommand("select * from [Joint Restraint Assignments]" & fi.Name, objConn)

So, you take the filename from the openfiledialog and use the FileInfo object to extract the directory name and the filename. Instead, you can use the methods I gave you, to get those values from the filename property of the file dialog, directly. I am at a loss how you think what I have been saying takes away from your using a dynamic filename. If the filename was fixed, you'd type in the values in your code, not use methods to work them out, surely ?

rajulama26-Apr-09 23:30

26-Apr-09 23:30

that means my no need to establish a connection. Do you mean to do something like:
Dim fi As New FileInfo(OpenFileDialog1.FileName)
path.GetFileName(&fi.name)
Dim objCmdSelect As New OleDbCommand("select * from [Joint Restraint Assignments]" .....)

???

or,

path.getfilename(openfiledialog1.filename)
Dim objCmdSelect As New OleDbCommand("select * from [Joint Restraint Assignments]" .....)

rajulama26-Apr-09 23:51

26-Apr-09 23:51

i think i got it. But I am confused about the data source to be use in oledbconnection:

Path.GetFileName(OpenFileDialog1.FileName) 
Dim con As OleDbConnection = New OleDbConnection("Provider=Microsoft.jet.oledb.4.0;data source=???")

Christian Graus26-Apr-09 23:53

26-Apr-09 23:53

Dim path as String =Path.GetFileName(OpenFileDialog1.FileName)

will give you the path in a variable. Just calling GetFileName without storing the result, does nothing.

rajulama27-Apr-09 0:02

27-Apr-09 0:02

thanks i got it. so what should be the data source in:

Dim path1 As String = Path.GetFileName(OpenFileDialog1.FileName)
  Dim con As OleDbConnection = New OleDbConnection("Provider=Microsoft.jet.oledb.4.0;data source=???")

rajulama27-Apr-09 0:10

27-Apr-09 0:10

Dim con As OleDbConnection = New OleDbConnection("Provider=Microsoft.jet.oledb.4.0;data source=" & path1 & "")

above code works. Thank you very very much

rajulama27-Apr-09 0:13

27-Apr-09 0:13

Eddy Vluggen26-Apr-09 22:54

Eddy Vluggen

26-Apr-09 22:54

Are you viewing the contents of table1 in MS Access while debugging? If so, MS Access is the one that's locking the database Frown | :(

I are troll Smile | :)

rajulama26-Apr-09 22:55

26-Apr-09 22:55

thanks.
no i m not. the access database as well as the table is not open.

Luc Pattyn27-Apr-09 1:04

Luc Pattyn

27-Apr-09 1:04

rajulama wrote:
Dim sConnectionString As String = "..." & fi.DirectoryName

Trying to open a directory as a database?

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

Avoiding unwanted divs (as in "articles needing approval") with the help of this FireFox add-in

Create an exe without need of setup file and packaging and deployment advice

Dave Kreskowiak27-Apr-09 2:12

Dave Kreskowiak

27-Apr-09 2:12

rajulama wrote:
Dim sConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Extended Properties=;Data Source=" & fi.DirectoryName

The names used in your code, you're trying to open a directory as a database. You have to give it the path to the .MDB file, not just it's parent directory.

rajulama wrote:
Dim objCmdSelect As New OleDbCommand("select * from table1" & fi.Name, objConn)

On top of that, your SQL query to get the data in table1 (if it even exists in that database) is wrong. You appending the filename to the end of the SQL SELECT statement, which won't work. The filename goes in the Data Source if your connection string, not the SELECT statement.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

jinxster26-Apr-09 22:30

jinxster

26-Apr-09 22:30

Dear Coders,

At the risk of asking a stupid question, or at least a question that has been answered before many times.

How would one go about the following situation. I have an application which comprises the following:

1. VB.NET 2008 Windows Forms application
2. MySQL
3. Framework 3.5
4. Crystal Reports
5. Infragistics UI controls
6. COM controls (to connect to MySQL database)

I would like to package and deploy this application so that the user can do this without requiring much computer savvy. (Pretty much standard exam question it seems)

Currently I do the installation myself and have taught one person how to install without me. Basically the steps include:

1. Install dotnexfx35.exe (not much user intervention)
2. Install MySQL (configuration is a bit above non computer savvy)
3. Install Crystal Runtime (not much user intervention so is good)
4. Run a bat file that copies the 2 COM files to %windowsroot%\system and runs regsvr32 on each.
5. Included Infragistics the first time in a deployment
6. Install setup

What I would like to do is, create an autorun.ini and an exe on a CD that brings up a menu that can install the various components. However, how (in VB 2008) can I make an exe that does not need to be installed first?

Do you think I am going about this the right way?

Re: Create an exe without need of setup file and packaging and deployment advice

Christian Graus26-Apr-09 22:46