Migration files have an UP and a DOWN function.
UP changes the database to the new desired state.
DOWN changes the database back to the state it was previously in.
Console commands:
npm run migrate runs the UP function
npm run migrate-undo runs the DOWN function
npm run seed inserts data to the database based on seed files
npm run seed-undo deletes the seeded data
SequelizeMeta table contains the migration history of the database. DO NOT REMOVE IT!
Example:
If version 1.0 of database is the current one.
UP -> Version 1.1
UP -> Version 1.2
DOWN -> Version 1.1
UP -> Version 1.2