Postgres 12

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create table favorite_movies(movie_id int, user_id int);

CREATE TABLE


with 
	param (movie_id, user_id) as (select 577922, 5),
	del as (
		delete from favorite_movies m
		using param p
		where m.movie_id = p.movie_id and m.user_id = p.user_id
		returning 1
)
insert into favorite_movies (movie_id, user_id) 
select p.* 
from param p
where not exists (select 1 from del)

INSERT 0 1


select * from favorite_movies;


movie_id
user_id


577922
5



SELECT 1


with 
	param (movie_id, user_id) as (select 577922, 5),
	del as (
		delete from favorite_movies m
		using param p
		where m.movie_id = p.movie_id and m.user_id = p.user_id
	returning 1
)
insert into favorite_movies (movie_id, user_id) 
select p.* 
from param p
where not exists (select 1 from del)

INSERT 0 0


select * from favorite_movies;


movie_id
user_id



SELECT 0