[RESOLVED] Logical OR functionality

blaster_master

If there're a number of rows in a column of table, each row with binary values, how can one do a logical OR on all of them (using PHP to retrieve the binary data from a SQL server)? [see baby-appendix below for a description of OR]

As an example, assume my_table has a column called 'bin' with 5 rows:
00010001
10000100
00001000
00111101
00010101

The OR of the above would be:
10111101

I'd like my PHP code to do the above functionality. Here's my thought (in pseudo-code):

set $n=0
fetch all the rows under 'bin'
compare the n'th value of all of the rows with '1' (so when $n=0, only the very left bit (Most Sig. Bit) of all the rows are compared)
if TRUE then the n'th bit of answer is '1', else '0'
$n++
jump back to the comparison step

The 3rd and 4th steps are the ones that are bothering me... Any help would be greatly appreciated.

baby-appendix:

OR: a logical gate used in electrical circuits. Its functionality is simple:
0 OR 0 -> 0
0 OR 1 -> 1
1 OR 0 -> 1
1 OR 1 -> 1

So when n digits are OR'd, if one of them has a value of '1' then the answer is '1', otherwise it's '0'.

barand

try

$bin = array(
        '00010001',
        '10000100',
        '00001000',
        '00111101',
        '00010101'
);
$res = array();

for ($i=0; $i < 8; $i++) {
    foreach($bin as $b) {
            $res[$i] |= $b[$i] ? 1 : 0;
    }
}
// show result
foreach ($res as $b) echo $b;

blaster_master

Excellent! Thank you.