The best and easy way to handle database migrations (version control)

Do know about database version control? It's called migrations and here I will tell you how to do it in a simple way.

If you know about it and work with JavaScript, you probably have tried one of these tools to handle database migrations: Sequelize, TypeORM, Bookshelf, etc… But, seriously… Are you happy with these options? I'm not.

Since I started to work with Java and met the beautiful Flyway, I was missing a tool as great as it is in another languages. And now comes the good news: there's a "dockerized" version that you can use with any language you want!

So if you trust me, keep reading about this magical tool.

The examples bellow are here: https://github.com/arojunior/tests-with-nodejs-graphql

	version: "3"
	services:
	flyway_mysql:
	image: boxfuse/flyway:5.2.4
	command: "flyway migrate"
	volumes:
	- ./docker/mysql/migrations/config:/flyway/conf
	- ./docker/mysql/migrations/sql:/flyway/sql

view raw flyway-docker-compose.yml hosted with ❤ by GitHub

Then we can create the config file and the migrations, as you can see in the volumes arguments.

folder tree

	flyway.driver=com.mysql.jdbc.Driver
	flyway.url=jdbc:mysql://mysql:3306/mydb?autoReconnect=true&useUnicode=true&characterEncoding=utf-8
	flyway.user=user
	flyway.password=password

view raw flyway.conf hosted with ❤ by GitHub

Those names for the migration files are following a convention that you can find here in the documentation, but it's very simple:

filenames convention

Did you notice that the file extension is .sql? Yes! You are able to write plain SQL scripts and don't need to learn a new syntax or object mappings. That's what I love in this tool.

	CREATE TABLE post
	(
	id int PRIMARY KEY AUTO_INCREMENT,
	content text,
	likes int,
	dislikes int,
	created datetime
	);

view raw V0001__create_table_post.sql hosted with ❤ by GitHub

	INSERT INTO post VALUES (0, 'Description 1', 0, 0, '2019-01-19 17:00:00');
	INSERT INTO post VALUES (0, 'Description 2', 0, 0, '2019-01-19 17:00:00');
	INSERT INTO post VALUES (0, 'Description 3', 0, 0, '2019-01-19 17:00:00');
	INSERT INTO post VALUES (0, 'Description 4', 0, 0, '2019-01-19 17:00:00');

view raw V0002__populate_table_post.sql hosted with ❤ by GitHub

Flyway will create a table to manage the migrations and it runs automagically every time you start the container. It will check the applied scripts and run the new ones. No additional command is needed, you just have to create the new files in the specified folder.

Flyway supports also SQL Server, Postgres, Oracle, MariaDB and more…

Take a look in the documentation for more infos: https://flywaydb.org/documentation/migrations

Now clap your hands for this amazing tool.

---