Multiplying 2 Rows of a Table?

fr600

The table looks sth like this...

CREATE TABLE files (
  file_id int(10) unsigned NOT NULL auto_increment,
  name varchar(255) NOT NULL default '',
  size bigint(20) unsigned NOT NULL default '0',
  downloads int(10) unsigned NOT NULL default '0',
  PRIMARY KEY  (id),
  UNIQUE KEY id (id)
) TYPE=MyISAM;

INSERT INTO users files (1, 'file1', 10000, 50);
INSERT INTO users files (2, 'file2', 70000, 10);

Now, I want to calculate ( size * downloads ) for all rows, like for this one it would be...

10000 50 = 500000
70000 10 = 700000

TOTAL TRANSFERED = 1200000 bytes

I know it's simple but I don't know how to do this. Can anyone help me with this?

fr600

After trying this code it says:

Fatal error: Unsupported operand types in d:\Apache\htdocs\new\total.php on line 17

and line 17 in total.php is:
$data += $row;

kburger

$sql = "SELECT (size * downloads) AS something FROM files";
$query = mysql_query($sql);
$data = 0; // 0 bytes
while($row = mysql_fetch_array($query))
  $data += $row['something'];

echo 'Total -> '.$data;

tekky

how about...

/*
SELECT (size*downloads) AS total FROM user_files GROUP BY file_id

and...
 */ 
$result = mysql_query($query);
$total = 0;
while($row = mysql_fetch_assoc($result))
  $total += $row['total'];
echo 'Total is: ' . $total . ' bytes.';

I see now reason why this wouldnt work...

fr600

$res = mysql_query("SELECT (size * downloads) FROM files");
$total = 0;
while ($row = mysql_fetch_array($res)) {
$total = $total + $row[0];
}

I've used this its working well...

Although I don't understand the actual difference between your code and this code 😕

tekky

fr600 wrote:
$res = mysql_query("SELECT (size * downloads) FROM files");
$total = 0;
while ($row = mysql_fetch_array($res)) {
$total = $total + $row[0];
}
I've used this its working well...

Although I don't understand the actual difference between your code and this code 😕

I included the GROUP BY clause because sometimes MySQL complains about not using GROUP BY on queries that do things like this or SUM() etc etc.

either should work