title: Azure seamless upgrade when database schema changes
body: <p>Let's say I have a production and staging deployment both using their own (SQL Azure) databases. If the schema in staging has changed and needs to be deployed to production is there a defined way of achieving the database upgrade on the production database (without downtime)?</p>
  
  <p>e.g. If I swap VIP staging &lt;-> production (and at same time automate changing connection strings somehow) what is the best process to automate upgrading the sql azure database.</p>
  
  <p>My thought would be to spot the environment change in RoleEnvironmentChanging (though not sure that VIP swap even fires RoleEnvironmentChanginng) and run the sql script against the to-be database (i.e. prod) at that point, however I need to make sure that script is only run once and there will be multiple instances transitioning. </p>