title: Are locked records from Django select_for_update affected by updated values
body: <p>I know that select_for_update locks the records that are being queried if we have more than one concurrent user. But does it also affect the evaluation of the queried records.</p>
  
  <p>For example, if user A and user B Query the table 'Jobs' at the same time based on a single variable 'Available' which is a Boolean.
  Both users would like to access records of available jobs (where Available = True). </p>
  
  <p>User A managed to be queued first and the records he is accessing are now locked for user B.</p>
  
  <p>If user A changes all records to False, does user B not get any records? Or does he get the same records as user A but with Availability equal to False?</p>
  
  <p>Also, does select_for_update() work with MySQL? Or does it have a different solution for concurrent queries?</p>