Database

ORMs are very complex pieces of software that can create more problems than they solve. With that in mind, Tram places a strong emphasis on SQL native concepts.

That said, working exclusively with SQL can get verbose, tiring, and introduce trivial mistakes.

To that end, Tram does use an ORM, but it is in no way an escape hatch from SQL, or a way to avoid writing SQL. You need to know SQL.

Default Database

Tram uses Postgres by default. Any database with a JDBC driver should be compatible, but some features assume Postgres, and this documentation assumes Postgres.

The starter template includes a dockerfile to let you run postgres locally with docker-compose up.

There is also a script bin/db-init that will initialize project databases for development.

Toucan2

The ORM tram uses is called Toucan2. It's an amazing library, and Tram would not exist without it. Most of the required functions are re-exported from the tram.db namespace.

Models

Read more about how models work in associations and models.

Configuration

Database configuration is controlled via the tram.edn file. You have 3 environments, and they all have their own database config, :db.

You can configure these to match whatever values you need. Values from the environment can be read with the reader macro #env ENV_VAR.