Question

I have a csv-files like this, names.csv:

"id","name"
"1","John"
"2","Joe"
"3","Peter"
"4","Frank"
"5","Bill"
...
"2","Steve"
"5","James"
"2","Mark"
"4","Anthony"

I want to merge the “rows” with the same “id” so I reach the following result:

"id","name"
"1","John"
"2","Joe , Steve , Mark"
"3","Peter"
"4","Frank , Anthony"
"5","Bill , James"

I want to do this with php language, but I don’t get a solution.
By my self I made some code, but that makes to much work for my serverhost (loops in loops):

$myFile = "merged-names.csv";
$fh = fopen($myFile, 'w') or die("can't open file");

if (($handle = fopen("names.csv", "r")) !== FALSE) 
{
  $line = fgets($handle);
  $val = explode(",", $line);
  $max = (count($val))/2;

  for ($i=0; $i <= $max; $i+2)
  {
    $id = $val[$i];
    $name = $val[$i+1];
    $stringData = "\"".$id."\"".",";
    fwrite($fh, $stringData);
    $stringData = "\"".$name."\"";
    fwrite($fh, $stringData);

    for ($e=0; $e <= $max; $e+2)
    {
  if (strcmp($id, $val[$e]) == 0)
  {
        if($i != $e)
    {
      $stringData = "\"".$val[$e+1]."\"";
      fwrite($fh, $stringData);
        }
  }
    }

    $stringData = "<br>";
    fwrite($fh, $stringData);

  }
fclose($handle);
 }

Can someone help me with the right solution for this, seems so simply, problem?
Thank you in advance!

Answer 1

how about this…

$temp = array();
if (($handle = fopen("names.csv", "r")) !== FALSE) {
    while (($data = fgetcsv($handle, 1000, ",")) !== FALSE) {
        $name = $data[1];
        $id = $data[0];
        if (!isset($temp[$id]))
            $temp[$id] = array();
        $temp[$id][$name] = 1;
    }
    fclose($handle);
}
foreach ($temp as $k => $v) {
    echo $k.","."\"".implode(",", array_keys($v))."\""."\n";
}