title: Auto decrement T-SQL ID when deleting records?
body: <p>In one of our apps, we read in data from a file and expand it into several tables.  If any part of the file is corrupt, we halt the read, and delete whatever data got inserted.</p>
  
  <p>The issue, here, is that we have an auto-increment ID on one of the import tables, and when we remove a problem file, the ID continues from its post-import value, rather than its pre-import value.</p>
  
  <p>In other words...   </p>
  
  <ul>
  <li>ID starts at 50.  </li>
  <li>Insert 100 records, max ID is now 150.  </li>
  <li>Delete 100 records, max ID is still 150.  </li>
  <li>Insert 50 records, ID is 200.  </li>
  </ul>
  
  <p>We've "lost" the range of 100 records. Is there an "auto decrement" equivalent to go with the auto increment?</p>