restructure folders

databases/postgres/README.md

@@ -0,0 +1,72 @@
+# 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
+
+    ```shell
+    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
+
+    ```shell
+    createdb -O test_user testing_db
+    ```
+
+3. Initialize database
+
+    ```shell
+    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:
+
+    ```ini
+    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:
+
+    ```shell
+    cargo run
+    ```
+
+6. Using a different terminal send an HTTP POST request to the running server:
+
+    ```shell
+    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...**
+
+    ```shell
+    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).