There is no switching among environments
or wasting time learning the ins and outs of multiple environments.
??? The migration DSL abstracts the database-specific details for you, so you no longer
need to know the ins and outs of your specific database. Oftentimes, you don??™t even
need to know anything about the specific SQL that your database engine supports. You
can now switch among database engines with almost no extra effort (as long as the
Active Record database adapter supports migrations).
??? Since all of your database schema changes are now stored in migration scripts (which
should be versioned), you now have an audit trail of all your actions. The biggest advantage
to this is that you can rebuild your database from scratch regardless of the database
backend by simply running your migration scripts in sequential version order! If your
database supports the related database management SQL syntax, such as rollback statements,
you can also roll back from a given state to any previous state by simply executing
your migration scripts in reverse version number order.
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