PHP: Add missing dates in array

Question

I'm running the following query on my table:

SELECT DISTINCT(date(dateAdded)) AS dateAdded, count(*) AS count FROM clients WHERE (dateAdded BETWEEN '2012-06-15' AND '2012-06-30') GROUP BY dateAdded ORDER BY dateAdded ASC

That returns something like this:

2012-06-17 ¦ 5 
2012-06-19 ¦ 2 
2012-06-26 ¦ 3 
2012-06-30 ¦ 2

I need to be able to fill in any missing dates in the date range like so:

2012-06-15 ¦ 0 
2012-06-16 ¦ 0 
2012-06-17 ¦ 5 <--
2012-06-18 ¦ 0 
2012-06-19 ¦ 2 <--
2012-06-20 ¦ 0 
2012-06-21 ¦ 0 
2012-06-22 ¦ 0 
2012-06-23 ¦ 0 
2012-06-24 ¦ 0 
2012-06-25 ¦ 0 
2012-06-26 ¦ 3 <--
2012-06-27 ¦ 0
2012-06-28 ¦ 0 
2012-06-29 ¦ 0 
2012-06-30 ¦ 2 <--

I'd like to do this using a PHP loop of some sort, if possible. Any help would be greatly appreciated.

Answer 1

I like using a date iterator for this kind of problems:

class DateRangeIterator implements Iterator
{
      private $from;
      private $to;
      private $format;
      private $interval;

      private $current;
      private $key;

      function __construct($from, $to, $format = 'Y-m-d', $interval = '+1 days')
      {
            if (false === ($this->from = strtotime($from))) {
                  throw new Exception("Could not parse $from");
            }
            if (false === ($this->to = strtotime($to))) {
                  throw new Exception("Could not parse $to");
            }
            $this->format = $format;
            $this->interval = $interval;
      }

      function rewind()
      {
            $this->current = $this->from;
            $this->key = 0;
      }

      function valid()
      {
            return $this->current <= $this->to;
      }

      function next()
      {
            $this->current = strtotime($this->interval, $this->current);
            ++$this->key;
      }

      function key()
      {
            return $this->key;
      }

      function current()
      {
            return date($this->format, $this->current);
      }
}

To use it:

foreach (new DateRangeIterator('2012-04-01', '2012-04-30') as $date) {
    echo "$date\n";
}

You can customize the format in which the dates should appear as well as the interval it should increase by.

In your case you would need to store the MySQL results using the key as the array index, e.g.

[ '2012-04-01' => 'some event', '2012-04-06' => 'some other event' ];