To change the UDL file’s content in LabVIEW programmly is not easy too. Because UDL file  is unicode-formatted, and LabVIEW is quite limited in support to unicode. I had tried several ways to change the database file name in UDL file and save the UDL file to hard disk. And when I open the changed UDL again, I got “File corrupted” message. It seemed that it is not a good way.At last, I had to read the help file of Database Connectivity Toolset word by word to find a way to work round. Wow, I found out that the VI DB Tools Open Connection is a Polymorphic VI that accepts string and file path data types. Just append the Access database file’s path after “Provider=Microsoft.Jet.OLEDB.4.0; Data Source=”, and wire it to connection information connector of DB Tools Open Connection VI, and everything will be OK.  Everything get solved.

It is really a good habit to read the help file carefully.

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• December 24, 2008 -- Howto: Creating a Microsoft Data Link file (.UDL) for Connecting to Microsoft Access in LabVIEW (0)
• December 18, 2008 -- How to write and read Access database in LabVIEW (0)
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The way a .UDL file is initially created depends on your Windows installation. This can be created  desktop shortcut menu.

1. Right-click on the Desktop, or in the folder where you want to create the file.
2. Select “New” from the shortcut menu. If Microsoft Data Link is listed, select it.
3. Windows 2000 will most likely not have a Microsoft Data Link listed. If this is the case, please refer to the next section.

If no Microsoft Data Link is listed, the following steps should fix this.

1. Right-click on the desktop, or in the folder where you want to create the file.
2. Select New, then Text Document.
3. Give the Text Document any name with a .UDL extension (“Show file extensions” must be enabled in folder options).
4. A window will pop up warning that “If you change a filename extension, the file may become unusable. Are you sure you want to change it?” – select Yes.
5. You have now successfully created a .UDL file.

At this point you have a Microsoft Data Link file. In order to use this in a database application, a couple more tasks need to be accomplished. In this case, you need to link the .UDL file to an Access database.

1. Open Access. Select Blank Access Database and click OK.
2. In the File New Database window, save the Database in a location of your choice with any .MDB or .ACCDB extension name.
3. At this point you can close Access (just remember where you saved the database to).
4. Go back to the .UDL file that was created previously and double-click on it (this is where a link to the Access database is created).
5. Click the Provider tab. For .MDB files, select “Microsoft Jet 4.0 OLE DB Provider”. For .ACCDB files, select “Microsoft Office 12.0 Access Database Engine OLE DB Provider”.
6. Click the Connection tab. Navigate to the .MDB or .ACCDB Access Database that was created in step 2. Now, the .UDL file is ready to be used in LabVIEW.

Related Posts

• December 18, 2008 -- How to write and read Access database in LabVIEW (0)
• January 16, 2009 -- Access Different Access Database Files Programmatically in LabVIEW with Database Connectivity Toolset (2)
• July 10, 2009 -- Move Up and Down Tree Control Sub-items Programmatically in LabVIEW (0)
• April 20, 2009 -- Transfer More Than Text Message in Queue Between Loops in LabVIEW (2)
• March 16, 2009 -- How to Create Linked List in LabVIEW (0)
• March 8, 2009 -- A Note about Using Database Connectivity Toolset in LabVIEW (0)
• February 22, 2009 -- Build a Tri-State LED Indicator in LabVIEW (0)
• February 16, 2009 -- NI Announcing the LabVIEW 2009 Platform Beta Program (0)

For more information about the Microsoft Access automation classes, DAO or ADO classes refer to the Microsoft website and Developer Network.It is also possible to use Dynamic Data Exchange (DDE) communication between LabVIEW and Access. DDE is a Microsoft technology that preceded COM and ActiveX. DDE is NOT recommended as it is considered by most to be obsolete. However, examples still ship with LabVIEW that demonstrate how to communicate with MS Access using DDE. The examples are located in ..\LabVIEW\examples\comm\access.llb

Note: The LabVIEW Database Connectivity Toolset is the preferred method of database communication with LabVIEW. The LabVIEW Database Connectivity Toolset offers many powerful tools and extended capabilites for quickly accessing databases. The LabVIEW Database Connectivity Toolset offers connectivity to most popular databases through Microsoft ADO technology, complete SQL Functionality, and the ability to save records in XML format. It provides both easy-to-use and advanced functions to allow common database operations as well as detailed database accessibility. The LabVIEW Database Connectivity Toolset is sold separately or in the LabVIEW Enterprise Connectivity Toolset along with the LabVIEW Statistical Process Toolkit and the LabVIEW Internet Developers Toolkit.

Related Posts

• December 24, 2008 -- Howto: Creating a Microsoft Data Link file (.UDL) for Connecting to Microsoft Access in LabVIEW (0)
• January 16, 2009 -- Access Different Access Database Files Programmatically in LabVIEW with Database Connectivity Toolset (2)
• July 10, 2009 -- Move Up and Down Tree Control Sub-items Programmatically in LabVIEW (0)
• April 20, 2009 -- Transfer More Than Text Message in Queue Between Loops in LabVIEW (2)
• March 16, 2009 -- How to Create Linked List in LabVIEW (0)
• March 8, 2009 -- A Note about Using Database Connectivity Toolset in LabVIEW (0)
• February 22, 2009 -- Build a Tri-State LED Indicator in LabVIEW (0)
• February 16, 2009 -- NI Announcing the LabVIEW 2009 Platform Beta Program (0)