I need some Looping help

savj14

What I'm trying to do is loop through my user database 10 times, selecting 50 users are a time. I just don't know how to increment the users 50 at a time during the loop. So when the Loop is completed 500 users will be selected 50 at a time(I hope that makes sense)

So in the example below when it loops through, the $query should be:
$query = "SELECT FROM users WHERE id BETWEEN 51 AND 101";
$query = "SELECT FROM users WHERE id BETWEEN 102 AND 152";
And so on and so on

for($t=0; $t<10; $t++) {

$query = "SELECT * FROM users WHERE id BETWEEN 1 AND 50"; 
$result = mysql_query($query) or die(mysql_error());
while($row = mysql_fetch_array($result)){
//Do some stuff
}
}

I am lost on how to do this.......Thanks in advance

NogDog

for($ix = 0; $ix < 10; $ix++)
{
   $sql = "SELECT * FROM users ORDER BY id LIMIT 50 OFFSET " . $ix * 50;
   // run the query, output the results . . .
}

savj14

Great that worked thanks!

Instead of:
$query = "SELECT * FROM users WHERE id BETWEEN 1 AND 50";

How would use:
$query = "SELECT * FROM users WHERE id BETWEEN 501 AND 551";

And continue looping through users 500-1000, 50 at a time

savj14

I can't figure this out as per my above post

Anyone?

NogDog

Just add 500 to the offset?

$sql = "SELECT * FROM users ORDER BY id LIMIT 50 OFFSET " . $ix * 50 + 500;

(Ultimately this feels a bit too hard-coded to me, i.e. it should be more data-dependent. But since I don't know the underlying requirements and data structure, I don't really have any other suggestion.)

savj14

I tried this and now I get this error:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '500' at line 1

Without adding: + 500
it worked just fine......not sure what the issue is

NogDog

It's an operator precedence issue. Wrap the arithmetic expression at the end in parens:

$sql = "SELECT * FROM users ORDER BY id LIMIT 50 OFFSET " . ($ix * 50 + 500);