What's the easiest way to represent a bytea as a single integer in PostgreSQL?

Question

I have a bytea column that contains 14 bytes of data. The last 3 bytes of the 14 contain the CRC code of the data. I would like to extract the CRC as a single i

Answer 1

select get_byte(b, 11) * 65536 + get_byte(b, 12) * 256 + get_byte(b, 13)
from (values ('12345678901234'::bytea)) s(b);
 ?column? 
----------
  3289908