Matriz multidimensional PHP MYSQL

<?php
  require 'php/phpConnection.php';

  // ======================================================================
  // Create a join query (way faster than several separate ones!)
  $sqlquery =
    "SELECT SSSA.id, SSS5.educationalname" .
    " FROM supportstaff_section1_a SSSA" .
      " LEFT OUTER JOIN supportstaff_section5 SSS5 ON SSS5.id = SSSA.ID";


  // ======================================================================
  // Run the query and get our results
  $resultarray = array();
  if ($resource = mysql_query($sqlquery)) {
    while ($curarray = mysql_fetch_assoc($resource)) {
      // Create an array, if it doesn't exist
      if (!isset($resultarray[$curarray["id"]]))
        $resultarray[$curarray["id"]] = array();

      // Add to the array, if not null
      $curstring = (string) $curarray["educationalname"];
      if ($curstring != "")
        $resultarray[$curarray["id"]][] = $curstring;
    }
    mysql_free_result($resource);
  }


  // ======================================================================
  // Convert from a keyed array to a standard indexed array (0, 1, 2, etc.)
  $finalarray = array();
  foreach ($resultarray as $id => & $data) {
    // Start with just ID
    $newarray = array(
      "id" => $id
    );

    // Get the data, if we have any
    if (count($data))
      $newarray["educationalnames"] = & $data;

    // Add to our final array and clear the newarray
    $finalarray[] = & $newarray;
    unset($newarray);
  }


  // ======================================================================
  // Get the JSON of our result
  $jsonresult = json_encode($finalarray);


  // ======================================================================
  // Echo it to test
  echo $jsonresult;


  // ======================================================================
  // Close the database
  mysql_close($con);
?>

[
  {
    "id": "8m8wwy",
    "educationalnames": ["GCSE - English", "GCSE - Maths"]
  },
  {
    "id": "wiL7Bn"
  },
  {
    "id": "zAw6M1"
  }
]