sql-database

PostgreSQL Database Starter

This is a basic Hello World Encore application with a single API endpoint and a PostgreSQL database to keep track of how many times you've said hello.

Developing locally

When you have installed Encore, you can create a new Encore application and clone this example with this command.

encore app create my-app-name --example=sql-database

Using databases with Encore

In this starter app there is already a database defined, but let's take this opportunity to learn a bit about how Encore helps you create and use databases.

Encore treats SQL databases as logical resources and natively supports PostgreSQL databases.

To create a database, import encore.dev/storage/sqldb and call sqldb.NewDatabase, assigning the result to a package-level variable. Databases must be created from within an Encore service.

For example:

-- todo/db.go --
package todo

// Create the todo database and assign it to the "tododb" variable
var tododb = sqldb.NewDatabase("todo", sqldb.DatabaseConfig{
	Migrations: "./migrations",
})

// Then, query the database using db.QueryRow, db.Exec, etc.
-- todo/migrations/1_create_table.up.sql --
CREATE TABLE todo_item (
  id BIGSERIAL PRIMARY KEY,
  title TEXT NOT NULL,
  done BOOLEAN NOT NULL DEFAULT false
  -- etc...
);

As seen above, the sqldb.DatabaseConfig specifies the directory containing the database migration files, which is how you define the database schema. See the Defining the database schema section below for more details.

With this code in place Encore will automatically create the database when starting encore run (locally) or on the next deployment (in the cloud). Encore automatically injects the appropriate configuration to authenticate and connect to the database, so once the application starts up the database is ready to be used.

Defining the database schema

Database schemas are defined by creating migration files in a directory named migrations within an Encore service package. Each migration file is named <number>_<name>.up.sql, where <number> is a sequence number for ordering the migrations and <name> is a descriptive name of what the migration does.

On disk it might look like this:

/my-app
├── encore.app                       // ... and other top-level project files
│
└── todo                             // todo service (a Go package)
    ├── migrations                   // todo service db migrations (directory)
    │   ├── 1_create_table.up.sql    // todo service db migration
    │   └── 2_add_field.up.sql       // todo service db migration
    ├── todo.go                      // todo service code
    └── todo_test.go                 // tests for todo service

Each migration runs in order and expresses the change in the database schema from the previous migration.

The file name format is important. Migration files must be sequentially named, starting with 1_ and counting up for each migration. Each file name must also end with .up.sql.

The first migration usually defines the initial table structure. For example, a todo service might start out by creating todo/migrations/1_create_table.up.sql with the following contents:

CREATE TABLE todo_item (
    id BIGSERIAL PRIMARY KEY,
    title TEXT NOT NULL,
    done BOOLEAN NOT NULL DEFAULT false
);

Running locally

To run the application locally, make sure you have Docker installed and running. This is required to run Encore applications with SQL databases.

encore run

Using the API in the example

To see that your app is running, you can ping the API.

curl http://localhost:4000/hello/There

Open the developer dashboard

While encore run is running, open http://localhost:9400/ to view Encore's local developer dashboard.

Deployment

Deploy your application to a staging environment in Encore's free development cloud:

git add -A .
git commit -m 'Commit message'
git push encore

Then head over to the Cloud Dashboard to monitor your deployment and find your production URL.

From there you can also connect your own AWS or GCP account to use for deployment.

Now off you go into the clouds!

Testing

encore test ./...