Database Migrations

DBMate is a database migration tool, to keep your database schema in sync across multiple developers and your production servers. We have pre-installed it in your devcontainer

After that we can setup our migrations folder and the create a users migration.

Create a Migration

dbmate new user_tables
# Creating migration: crates/db/migrations/20220330110026_user_tables.sql

Edit the SQL file that was generated for you and add the following.

-- migrate:up
CREATE TABLE users (
    id SERIAL PRIMARY KEY, 
    email VARCHAR NOT NULL UNIQUE, 
    created_at TIMESTAMP NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMP NOT NULL DEFAULT NOW()
);

INSERT INTO users(email) VALUES('[email protected]');
INSERT INTO users(email) VALUES('[email protected]');
INSERT INTO users(email) VALUES('[email protected]');

-- migrate:down
DROP TABLE users;

Run the Migrations

List the migrations so we can see which have run.

dbmate status
#[ ] 20220330110026_user_tables.sql
#
#Applied: 0
#Pending: 1

Run our new migration.

dbmate up
#Applying: 20220330110026_user_tables.sql

And check that it worked.

psql $DATABASE_URL -c 'SELECT count(*) FROM users;'

And you should see

 count 
-------
      3
(1 row)

Your project folders should now look like this.

├── .devcontainer/
│   └── ...
└── crates/
│         web-server/
│         │  └── main.rs
│         └── Cargo.toml
│         db/
│         ├── migrations
│         │   └── 20220330110026_user_tables.sql
│         └── schema.sql
├── Cargo.toml
└── Cargo.lock