examples/database_interactions/pg

async_pg example

This example illustrates

• tokio_postgres
• use of tokio_pg_mapper for postgres data mapping
• deadpool_postgres for connection pooling
• dotenv + config for configuration

Instructions

1. Create database user

   createuser -P test_user
   

   Enter a password of your choice. The following instructions assume you used testing as password.

   This step is optional and you can also use an existing database user for that. Just make sure to replace test_user by the database user of your choice in the following steps and change the .env file containing the configuration accordingly.

2. Create database

   createdb -O test_user testing_db
   

3. Initialize database

   psql -f sql/schema.sql testing_db
   

   This step can be repeated and clears the database as it drops and recreates the schema testing which is used within the database.

4. Create .env file:

   SERVER_ADDR=127.0.0.1:8080
   PG.USER=test_user
   PG.PASSWORD=testing
   PG.HOST=127.0.0.1
   PG.PORT=5432
   PG.DBNAME=testing_db
   PG.POOL.MAX_SIZE=16
   

5. Run the server:

   cargo run
   

6. Using a different terminal send an HTTP POST request to the running server:

   echo '{"email": "ferris@thecrab.com", "first_name": "ferris", "last_name": "crab", "username": "ferreal"}' | http -f --json --print h POST http://127.0.0.1:8080/users
   

   ...or using curl...

   curl -d '{"email": "ferris@thecrab.com", "first_name": "ferris", "last_name": "crab", "username": "ferreal"}' -H 'Content-Type: application/json' http://127.0.0.1:8080/users
   

   A unique constraint exists for username, so sending this request twice will return an internal server error (HTTP 500).