PostgreSQL INSERT ON CONFLICT UPDATE (upsert) use all excluded values

Question

When you are upserting a row (PostgreSQL >= 9.5), and you want the possible INSERT to be exactly the same as the possible UPDATE, you can write it like this:

INSERT INTO tablename (id, username, password, level, email) 
                VALUES (1, 'John', 'qwerty', 5, 'john@mail.com') 
ON CONFLICT (id) DO UPDATE SET 
  id=EXCLUDED.id, username=EXCLUDED.username,
  password=EXCLUDED.password, level=EXCLUDED.level,email=EXCLUDED.email

Is there a shorter way? To just say: use all the EXCLUDE values.

In SQLite I used to do :

INSERT OR REPLACE INTO tablename (id, user, password, level, email) 
                        VALUES (1, 'John', 'qwerty', 5, 'john@mail.com')

Answer 1

Postgres hasn't implemented an equivalent to INSERT OR REPLACE. From the ON CONFLICT docs (emphasis mine):

It can be either DO NOTHING, or a DO UPDATE clause specifying the exact details of the UPDATE action to be performed in case of a conflict.

Though it doesn't give you shorthand for replacement, ON CONFLICT DO UPDATE applies more generally, since it lets you set new values based on preexisting data. For example:

INSERT INTO users (id, level)
VALUES (1, 0)
ON CONFLICT (id) DO UPDATE
SET level = users.level + 1;