title: Add/Update from Offline DBs to Central DB - Access
body: <p>I've got a somewhat unique problem due to our infrastructure. I have two <strong>offline</strong> tablet's which are performing a survey and entering the information in an Access database. These tablets have their own copy of the database front end AND back end.</p>
  
  <p>I need to, at the end of every day, update the master copy of the back-end (on an office computer) with the values in each of the two tablet databases. This master DB is then uploaded to each of the tablets, replacing their incomplete versions, and off they go the next day.</p>
  
  <p>I've never done this sort of merging before and don't really know where to start. Basically, I need a query which will:</p>
  
  <ul>
  <li>Delete the current values in the master DB</li>
  <li>Add the values from tablet1, merged with the values of tablet2 into the master DB</li>
  </ul>
  
  <p>I can delete the current values in the master DB because the tablets will contain the values from the days before as well (as they are sometimes needed for reference etc). Basically, the tablets will always contain the <code>entire database + today's survey</code>. It's just that <code>+ today's survey</code> is different for each tablet.</p>
  
  <p>Is it possible to do? How can I keep the ID fields, as there are relationships in place using KeyIDs?</p>
  
  <p>I need <code>MERGE</code>, but havn't found any documentation on if it works in MS Access... MS seems to play with the standards however they please. Or maybe MSA2010 just hasn't updated to support Merge?</p>