Docker postgreSQL entrypoint-initdb.d choose database - postgresql

Question

I have a docker-compose.yml file
version: '3'
services:
postgres:
image: postgres:13.1
healthcheck:
test: [ "CMD", "pg_isready", "-q", "-d", "postgres", "-U", "root" ]
timeout: 45s
interval: 10s
retries: 10
restart: always
environment:
- POSTGRES_USER=root
- POSTGRES_PASSWORD=password
- APP_DB_USER=docker
- APP_DB_PASS=docker
- APP_DB_NAME=docker
volumes:
- ./db:/docker-entrypoint-initdb.d/
ports:
- 5432:5432
in the same directory there is a directory db with 1 file init.sql:
CREATE TABLE accounts (
user_id serial PRIMARY KEY,
username VARCHAR ( 50 ) UNIQUE NOT NULL,
password VARCHAR ( 50 ) NOT NULL,
email VARCHAR ( 255 ) UNIQUE NOT NULL,
created_on TIMESTAMP NOT NULL,
last_login TIMESTAMP
);
insert into accounts(username,password,email,created_on) values ('a','aaa','assdfdas',now())
when I run docker-compose up (if the db is empty) the init.sql file is executed but the database in which it is executed is root and not postgres, How can I change it?
Imgur link to DataGrip screenshot

Answer 1

You can use the psql command \connect <db-name> inside your init.sql file in order to connect to the correct database (given that the database already exists).
In your case, the init.sql file would look something like:
\connect postgres <-- connects to the 'postgres' database
CREATE TABLE accounts (
user_id serial PRIMARY KEY,
username VARCHAR ( 50 ) UNIQUE NOT NULL,
password VARCHAR ( 50 ) NOT NULL,
email VARCHAR ( 255 ) UNIQUE NOT NULL,
created_on TIMESTAMP NOT NULL,
last_login TIMESTAMP
);
...