Take a look into .env and compose.yaml files for the details on each setting and each env variable

• Docker is installed on your computer
• Copy the content of .env.example to the .env file

docker compose up

You shall see docker containers pulling 2 images: pgadmin and postgres respectively. pgadmin is not necessary, but just in case you prefer to work with databases in a visual manner

Then, that's how the successful start of the containers looks like:

[+] Running 3/3
 ✔ Network docker-pg_default Created 0.0s
 ✔ Container postgres Created 0.3s
 ✔ Container pgadmin Created 0.3s

1. Open localhost:5050 in your browser and login with the pgadmin credentials specified in the .env file
2. Register new server:
   • General. Name: any name you prefer
   • Connection. Host name/address: host.docker.internal
   • Connection. Port: port as specified in your compose.yaml - services.postgres.ports
   • Connection. Database: as specified in .env - POSTGRES_DB
   • Connection. Password: as specified in .env - POSTGRES_PW

Now you can find your server in the pgadmin Object Explorer

In a terminal, type:

docker exec -it <CONTAINER_NAME | CONTAINER_ID> psql -U <POSTGRES_USER> <POSTGRES_DB>

• CONTAINER_NAME as specified in your compose.yaml file (services.postgres.container_name), or
• CONTAINER_ID is obtained using the command: docker ps

Simple an clear tutorial for psql commands

To see all available DBs:

\l

Select your DB (its name is specified in .env file under the name POSTGRES_DB):

\c <POSTGRES_DB>

List all tables:

\d

Create temporary table:

CREATE TABLE COMPANY(
 ID INT PRIMARY KEY NOT NULL,
 NAME TEXT NOT NULL,
 AGE INT NOT NULL,
 ADDRESS CHAR(50),
 SALARY REAL
);

Drop the table:

DROP TABLE COMPANY;

To quit:

\q

docker-compose down --volumes