limit output of the loop

zzz

I know this is basic but I can't get it straight.

I output some data from db via a loop

I need to set a max limit for output, say 25. When Max limit is reached I need to stop the output and print something like:

more...

Having a mental block...


$count = 1;

foreach ($something as $smth) { 

  ...

  $count++;

  if ($count == 25) {
     break; 
  }
}

What am I missing here?

bradgrafelman

Here's one way of doing it:

for($i = 0; $i < 25 && $row = array_shift($data); $i++) {
	// do stuff with $row here
}

if(!empty($data)) {
	// loop didn't get all of $data, output "more" info here
}

Note that it's rather destructive in that the data processed in the for() loop is removed from the array.

Then again, why are you retrieving more rows from the database than what you actually want? That seems rather wasteful; why not do a "SELECT SQL_CALC_FOUND_ROWS ... LIMIT 25" and then "SELECT FOUND_ROWS()" to determine if more than 25 rows were found in the DB (even though only 25 were returned)?

Kudose

If you are getting the results in an indexed array, you could use:

foreach($result as $key => $set):
  if($key >= 25)
    break;
endforeach;

also

<?php

    $set = range(0, 99);

    foreach($set as $key => $value){
            if($key == 25) break;
            echo $key;
    }

nevvermind

$count = 0;

foreach ($something as $smth) {

  ...

  if ($count++ == 25) break;
}

zzz

bradgrafelman;10960098 wrote:
Then again, why are you retrieving more rows from the database than what you actually want? That seems rather wasteful; why not do a "SELECT SQL_CALC_FOUND_ROWS ... LIMIT 25" and then "SELECT FOUND_ROWS()" to determine if more than 25 rows were found in the DB (even though only 25 were returned)?

Yes, it looks odd. What I do is loop through an array that has names of categories. Then, from within each category I make a separate query to a db table to retrieve rows that belong to a particular user and that fall under that category.

It seems the only way for me to insert category headers above resultrs

CATEGORY 1

row 1
row 2

CATEGORY 2

row 1
row 2
row 3

zzz

nevvermind;10960101 wrote:

$count = 0;

foreach ($something as $smth) {

  ...

  if ($count++ == 25) break;
}

I've tried exactly this but for some reason it's not working in my case. Need to figure out why...

bradgrafelman

zzz wrote:
Then, from within each category I make a separate query to a db table to retrieve rows that belong to a particular user and that fall under that category.

It seems the only way for me to insert category headers above resultrs

Sounds like you're in need of some SQL optimizations in the form of a JOIN or two.

zzz

It's possible. I learn every day. There are quite a few LEFT and INNER JOINS on my site 🙂

johanafm

If you join the data together, all you have to do is order by category, and keep track of the category for the previous row. Whenever category has changed, you need to display a new category header.