SELECT *
FROM table
WHERE some_id = ANY(ARRAY[1, 2])
or ANSI-compatible:
SELECT *
FROM table
WHERE some_id IN (1, 2)
The ANY syntax is preferred because the array as a whole can be passed in a bound variable:
SELECT *
FROM table
WHERE some_id = ANY(?::INT[])
You would need to pass a string representation of the array: {1,2}