title: How to migrate partial data to another database
body: <p>This is my first time facing this problem and I'm not really sure how to pursue it.</p>
  
  <p>We've got a site with information on a couple hundred doctors and I need to move all the 'doctors' from one mySQL database to another.  It's a Drupal site and the information is split up among maybe 20 different tables.  The new database is also a Drupal site with the same table structure, but also has new information that can't be lost.</p>
  
  <p>How should I go about getting specific rows from specific tables over to the new database? </p>
  
  <p>And to make it a little harder, all the row ids are auto-incremented.  I'll need to insert them with whatever index id comes next and then update that id in the other related tables. What has to happen in order to get this done?</p>