UPDATE

UPDATE table [[AS] alias] SET col = expr [, …]
[FROM relation] [WHERE expr] [RETURNING targets]

UPDATE users SET name = 'ADA' WHERE id = 1;
UPDATE users AS u SET name = upper(name) FROM orders o WHERE o.user_id = u.id;
UPDATE inventory i SET reserved = x.reserved_units
  -- implicit alias (no AS), derived-table source
FROM (SELECT product_id, SUM(quantity) AS reserved_units FROM order_items GROUP BY product_id) x
WHERE i.product_id = x.product_id;
UPDATE events SET payload['team'] = '"engine"' WHERE id = 7;
UPDATE customers SET credit_limit = credit_limit + 100 WHERE id = 100 RETURNING id,
  credit_limit;
UPDATE users SET name = 'x' WHERE id = 1 RETURNING *;
UPDATE users SET name = 'x' WHERE id = 1 RETURNING users.id, users.name, id + 1;