For any new environments and databases, you can use just drizzle-kit migrate, and all the migrations together with init will be applied

When you run migrate on a database that already has all the tables from your schema, you need to run it with the drizzle-kit migrate --no-init flag, which will skip the init step. If you run it without this flag and get an error that such tables already exist, drizzle-kit will detect it and suggest you add this flag.

When you introspect the database, you will receive an initial migration without comments. Instead of commenting it out, we will add a flag to journal entity with the init flag, indicating that this migration was generated by introspect action

root@51a758d136a2:~/test/test-project# npx prisma migrate diff --from-empty --to-schema-datamodel prisma/schema.prisma --script > migration.sql root@51a758d136a2:~/test/test-project# cat migration.sql -- CreateTable CREATE TABLE "test" ( "id" SERIAL NOT NULL, "val" INTEGER, CONSTRAINT "test_pkey" PRIMARY KEY ("id") ); root@51a758d136a2:~/test/test-project# mkdir -p prisma/migrations/initial root@51a758d136a2:~/test/test-project# mv migration.sql prisma/migrations/initial/

# Optionally, you can write a description for the migration, which you can use for # documentation and changelogs. describe 'The _id suffix has been removed from the author property in the Articles API.'

If you need to ensure migrations run in a certain order with regular db:migrate, set up Outrigger.ordered. It can be a hash or a proc that takes a tag; either way it needs to return a sortable value: Outrigger.ordered = { predeploy: -1, postdeploy: 1 } This will run predeploys, untagged migrations (implicitly 0), and then postdeploy migrations.

The code will work without exception but it doesn’t set correct association, because the defined classes are under namespace AddStatusToUser. This is what happens in reality: role = AddStatusToUser::Role.create!(name: 'admin') AddStatusToUser::User.create!(nick: '@ka8725', role: role)

this gem promotes writing tests for data migrations providing a way allows to write code that migrates data in separate methods.

having the code migrates data separately covered by proper tests eliminates those pesky situations with outdated migrations or corrupted data.

There are three keys to backfilling safely: batching, throttling, and running it outside a transaction. Use the Rails console or a separate migration with disable_ddl_transaction!.

Active Record creates a transaction around each migration, and backfilling in the same transaction that alters a table keeps the table locked for the duration of the backfill. class AddSomeColumnToUsers < ActiveRecord::Migration[7.0] def change add_column :users, :some_column, :text User.update_all some_column: "default_value" end end