Migrations

Migrations are plain SQL files in the migrations/ directory, run with sql-migrate. Since they are embedded into your binary, a deployed application carries its own schema history.

Writing Migrations

Migration files are named sequentially with a short description, such as 0001_initial.sql and 0002_create_rockets.sql. Each file has an up and a down section:

migrations/0002_create_rockets.sql

-- +migrate Up
CREATE TABLE rockets (
    id         TEXT PRIMARY KEY,
    created_at TIMESTAMP NOT NULL DEFAULT NOW(),
    name       TEXT NOT NULL,
    fuel       BIGINT NOT NULL DEFAULT 0
);

CREATE INDEX idx_rockets_name ON rockets (name);

-- +migrate Down
DROP TABLE IF EXISTS rockets;

Running Migrations

During development, you rarely need to think about migrations since copper run applies any pending ones before starting your application. If you would like to skip this, pass -migrate=false. You may also run migrations on their own:

copper migrate

To roll back, pass the direction:

copper migrate -direction=down

down reverts only the most recent migration. You may run it again to step back further.

Migrations in Production

copper build compiles a standalone migrator alongside your app:

copper build
./build/migrate.out -config config/prod.toml    # apply pending migrations
./build/app.out -config config/prod.toml        # start the app

Run the migrator as a deploy step before starting (or restarting) the app. To roll back the most recent migration, set the direction with -set:

./build/migrate.out -config config/prod.toml -set 'csql.migrations.direction="down"'

The value is parsed as TOML, so the inner quotes matter. All of the [csql.migrations] keys are listed in the Configuration Reference.

Getting Started

The Basics

Architecture

HTTP

Database

Frontend

Digging Deeper

Reference

Writing Migrations

Running Migrations

Migrations in Production

​Writing Migrations

​Running Migrations

​Migrations in Production

Writing Migrations

Running Migrations

Migrations in Production