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Microsoft Access 2010 by default uses the .accdb file format extension introduced in Access 2007. Access continues to provide some support for the file format used in earlier versions of Access. This article explains why you should use the new file format whenever possible, and why you might need to use the earlier version file format in some instances. You will also learn explicitly how to convert a database to the new file format.

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The new file format (.accdb)

Access 2010 employs a file format that supports a number of product enhancements. When you create a new database, the database uses the new file format by default and is given the .accdb file extension.

You should use the new file format whenever possible because it supports new features, such as multivalued fields and attachments. Moreover, if you want to convert your desktop database to a Web database by using Access Services, the desktop database file must be in .accdb format.

However, the new file format cannot be opened or linked to with earlier versions of Access, it does not support replication, and it does not support user-level security. If you need to use the database with earlier versions of Access, or if you need to use replication or user-level security, you must use an earlier version file format.

Features provided by the .accdb file format

  • Web publishing with Access Services    

    If you have a server running Access Services, a component of SharePoint Server, you can publish an .accdb file format to the Web, suibject to certain compatibility restrictions. Some design features and paradigms are different for Web databases than for desktop databases — some desktop databases cannot be published to the Web without first making design changes.

    After you publish a database to the Web, you can still open the .accdb file to make design changes, and can also then synchronize those changes with the published version. People can use the published Web database in a browser, without having Access installed.

  • Multivalued fields    

    Suppose you need to assign a task to one of your employees but decide that you need to assign it to more than one person. In Access 2010 you can create a multivalued field where the employees' names can be selected from or entered in a box.

    When you click the box, check boxes that are selected indicate your choices. The selected employees are stored in the multivalued field and are separated by commas (by default) when displayed.

    The idea behind multivalued fields is to make it easy to select and store more than one choice, without having to create a more advanced database design. Multivalued fields are also important for integration with Microsoft SharePoint Foundation, because SharePoint lists also support multivalued fields.

  • Attachment data type    

    The new Attachment data type lets you easily store all types of documents and binary files in your database without excessive growth in the physical size of the database. Attachments are automatically compressed, when appropriate, to maximize space usage. You can attach a Word document to a record, or save a series of digital pictures. You can even keep multiple attachments attached to a single record.

  • Improved integration with SharePoint and Outlook    

    In the past, Access files in the .mdb format were blocked by SharePoint or Outlook due to the fact that unsafe code can be included within an Access database. Access 2010 allows code to be either verified as safe or disabled. This makes it possible to integrate Access databases more fully with SharePoint or Outlook.

  • Memo field history tracking    

    Memo fields are useful for storing large amounts of information. Starting with Access 2007, you can set a property (AppendOnly) that forces Access to retain a history of all changes to a Memo field. You can then view a history of those changes. This feature also supports the versioning feature in Windows SharePoint Services 3.0 so that you can use Access to track changes in multiple lines of a text field that is stored in a SharePoint list (provided that the field has the Append Changes to Existing Text option set to Yes).

  • Improved encryption    

    You can choose to set a database password and encrypt the contents of your database. When you do so using Access 2007 and a file that uses the new file format, Access uses the Windows Crypto API to encrypt the data. Third-party encryption tools can also be used.

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The earlier version file format (.mdb)

Versions of Access earlier than Office Access 2007 support file formats that use the .mdb file extension. In Access 2010 you can still open .mdb files. If the file is stored in the Access 2002-2003 or Access 2000 file format, you can open it and use it in Access 2010 as you normally would. However, you cannot take advantage of the new features that require the .accdb file format.

If the file is stored in the Access 95 or Access 97 file format, when you first open it in Access 2010, Access offers to upgrade the database to the file format currently set as the default file format (usually the .accdb file format, unless you or an administrator has changed the setting). If you do not plan to use the database with versions of Access earlier than Access 2007, and you will not be sharing the database with other users who use versions of Access earlier than Access 2007, and you do not use replication or user-level security, you should upgrade the database file to the new .accdb format. After you upgrade the database to the .accdb file format, you can no longer open the database by using a version of Access earlier than Access 2007.

If the file is stored in Access 95 or Access 97 format and you choose not to upgrade to the .accdb format, you cannot make design changes. You can view objects and make changes to your data through Access 2010, but you cannot make design changes.

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Converting to the new file format

To explicitly convert an Access database to the new .accdb file format, you must first open the database and then save it in the .accdb file format.

Important: The following procedure is for files created in Access 97, Access 2000, Access 2002 or Access 2003.

First, open your database:

  1. Click the File tab.

  2. On the left, click Open.

  3. In the Open dialog box, select and open the database that you want to convert.

Now, convert your database:

  1. Click the File tab.

  2. On the left, click Share.

  3. Under Save Entire Database, click Save Database As.

  4. On the right, under Database File Types, click Access Database.

  5. In the Save As dialog box, in the File name box, enter a file name or use the file name supplied.

  6. Click Save.

    A copy of the database is created in the .accdb file format.

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