Contributing to Backend

Migrations

Create new migrations

You can generate new migrations with the diesel cli:

diesel migration generate migration_name

This will create two empty sql files that look something like this:

  • migrations/20160815133237_migration_name/up.sql
  • migrations/20160815133237_migration_name/down.sql

up.sql applies the migration and down.sql reverts the migration.

Now we have to write the migrations in the respective up.sql and down.sql files.

Examples:

-- up.sql
CREATE TABLE seeds (
  id SERIAL PRIMARY KEY,
);

-- down.sql
DROP TABLE seeds;

Apply migrations

diesel migration run

Redo migrations

This is especially useful for incremental improvements to the database. For example if you need to change one field in one of your tables, you can change it and redo the migration.

# Redo latest migration
diesel migration redo

# Or redo all migration
diesel migration redo --all