Is there a way to compare a single byte value to a bytea field in PostgreSQL?
For example: I have a bytea field with the value \x11AA22BB. The comparison to a byte value of AA should be true while the comparison to a byte value of 1A should be false.
The only way I see is to extract each byte from the bytea column separately with something like get_byte(string, offset) and check each one.
I have a bytea field with the value \x11AA22BB. The comparison to a byte value of AA should be true
It seems you're looking for the position function, knowing that it will return 0 if the byte is not contained in the string:
select position('\xAA'::bytea in '\x11AA22BB') > 0 AS contained;
contained
-----------
t
If the byte value is stored in an integer, set_byte can be used to place it into a bytea:
select position(set_byte('\x00', 0, 170) in '\x11AA22BB') > 0;