PHP dynamic rowspan for mysql results

dynamic_rowspan.php

<?php
/**
 * addRowspan
 * 
 * from an array of assoc mysql results, appends a column 'rowspan' by looking ahead
 * for keys with the same value.
 * 
 * @param string $span_key - key to base span on 
 * @param array $rows - 2d array of rows
 */
function addRowspan($span_key, &$rows) {
  for($i=0; $i<count($rows); $i++) {
    $rowspan = 1;
    for($j=$i; $j<$rows; $j++) {
      // lookahead
      if(isset($rows[$j+1])) {
          // this is not the last row...
          if ($rows[$j][$span_key] === $rows[$j+1][$span_key]) {
              // the next date is the same
              $rowspan++;
              // so set its rowspan to 0
              $rows[$j+1][$span_key] = 0;
              // and check the next
              continue;
          }
      }
      // here we have calculated the rowspan
      $rows[$i][$span_key] = $rowspan;
      // so jump ahead spanned rows in the main loop
      $i += $rowspan -1;
      break; // no more calculation necessary
    }
  }
}

Hi, thanks for the code, although having tried it, it does not appear append a column 'rowspan' but instead changes the span_key value to become the calculated rowspan value. Or maybe I'm missing something? Regards, RP

Good technique. Thank you!

in codeigniter its not worked how can i use this

Share a little improvement:

1. $span_key change to array
2. fixed append 'rowspan' array
3. added $unique_key avoid span confusion

function addRowspan($unique_key, $span_key, &$rows)
{
    for ($k = 0; $k < count($span_key); $k++) {
        for ($i = 0; $i < count($rows); $i ++) {
            $rowspan = 1;
            for ($j = $i; $j < $rows; $j ++) {
                // lookahead
                if (isset($rows[$j + 1]))
                {
                    // this is not the last row...
                    if ($rows[$j][$span_key[$k]] === $rows[$j + 1][$span_key[$k]] // the next date is the same
                        && 
                        $rows[$j][$unique_key] === $rows[$j + 1][$unique_key] // check next pk is the same
                    ) {
                        $rowspan ++;
                        // so set its rowspan to 0
                        $rows[$j + 1]['rowspan'][$span_key[$k]] = 0;
                        // and check the next
                        continue;
                    }
                }
                // here we have calculated the rowspan
                $rows[$i]['rowspan'][$span_key[$k]] = $rowspan;
                // so jump ahead spanned rows in the main loop
                $i += $rowspan - 1;
                break; // no more calculation necessary
            }
        }
    }
}

Call function:

addRowspan('field1', array('field1','field2','field3'), $rows);

HTML:

echo '<table border="1" style="border-collapse:collapse; font-size: 12px;">';
$pre_key = '';
foreach ($rows as $row) {
    echo '<tr>';
    if ($row['rowspan']['field1'])
    {
        echo "<td rowspan=".$row['rowspan']['field1'].">$row[field1]</td>";
    }
    if ($row['rowspan']['field2'])
    {
        echo "<td rowspan=".$row['rowspan']['field2'].">$row[field2]</td>";
    }
    if ($row['rowspan']['field3'])
    {
        echo "<td rowspan=".$row['rowspan']['field3'].">$row[field3]</td>";
    }
    echo "<td>$row[field4]</td>";
    echo "<td>$row[field5]</td>";
    echo "<td>$row[field6]</td>";
    echo '</tr>';
}
echo '</table>';