Postgres making arrays taking unique elements

uniqueArrayElement.sql

-- Written by Arsham Arya
-- Any contribution makes readers happy.

INSERT INTO table_name (user_id, my_array_field) 
VALUES (2233, array[112, 333]) 
ON CONFLICT (user_id) DO
UPDATE SET my_array_field = array(
  SELECT DISTINCT unnest(table_name.my_array_field || array[112, 333])
) WHERE table_name.user_id = 2233;

/* Tips 
sample user_id: 2233
sample array values: 112, 333
ON CONFLICT statment only works on postgres 9+ (IDK the exact version)
but you can use some techniques on older versions.
*/