Back when we talked about what's new under the hood in XenForo 2.4, we said we'd be focusing on developer tools and features that have become commonplace in other frameworks, such as Laravel. Today's HYS is a big one in that regard: database schema migrations.
If you've used migrations in pretty much any other modern framework this will all feel very familiar. If you haven't, don't worry, the concept is simple.
What is a migration?
A migration is a small file that describes one change to the database. Adding a table, adding a column, changing an index, converting some data, that sort of thing. Each migration has an up() method that makes the change and, optionally, a down() method that reverses it.
Migrations live in a _migrations...