Postgresql Trying to implement One-To-Many - database

Question

this is my first hands-on experience with Sql and I'm trying to construct One-To-Many relationship, here is the SQL code:
create table car (
id SERIAL PRIMARY KEY,
make VARCHAR(100) NOT NULL,
model VARCHAR(100) NOT NULL,
price NUMERIC(19, 2) NOT NULL
);
create table person (
id BIGSERIAL NOT NULL PRIMARY KEY,
first_name VARCHAR(50) NOT NULL,
last_name VARCHAR(50) NOT NULL,
gender VARCHAR(7) NOT NULL,
email VARCHAR(100),
date_of_birth DATE NOT NULL,
country_of_birth VARCHAR(50) NOT NULL,
cars_owning INT[] REFERENCES car(id)
);
and I get this error:
Key columns "cars_owning" and "id" are of incompatible types: integer[] and integer.
Here is the model a person can have many cars but each car have only one owner

Answer 1

typically (as a good general rule of thumb) the many refers to the one. not the other way around as you have tried.
So, alter the schema as:
create table car (
id SERIAL PRIMARY KEY,
make VARCHAR(100) NOT NULL,
model VARCHAR(100) NOT NULL,
price NUMERIC(19, 2) NOT NULL,
owner_id BIGINT FOREIGN KEY REFERENCES person(id)
);
create table person (
id BIGSERIAL NOT NULL PRIMARY KEY,
first_name VARCHAR(50) NOT NULL,
last_name VARCHAR(50) NOT NULL,
gender VARCHAR(7) NOT NULL,
email VARCHAR(100),
date_of_birth DATE NOT NULL,
country_of_birth VARCHAR(50) NOT NULL
);
If you need to get the list of cars owned by a person, use this select statement
SELECT person.id, ARRAY_AGG(car.id) owns_car_ids
FROM person
LEFT JOIN car ON person.id = car.owner_id
GROUP BY 1