Performance of fetching DB items individually vs looping with php -

out of curiosity, of these segments of code have faster performance time when implemented on mass scale?

let's have table members , want fetch photos.

method 1

$members = $db->query('select * members order id asc'); foreach($members $m)      $memberids[] = $m['id'];  $photos = $db->query('select * photos member in'.join(',', $memberids).' order id asc'); foreach($photos $p) {     // multi_arr_search(search_val, search_column, search_array) returns parent key in multi dimensional array     $memberarraykey = multi_arr_search($p['member'], 'id', $members);     $members[$memberarraykey]['photos'][] = $p; } 

or

method 2

$members = $db->query('select * members order id asc'); foreach($members $k=>$m)      $members[$k]['photos'] = $db->query('select * photos member='.$m['id'].' order id asc'); 

method 1 result in fewer queries being ran, requires more php work.

neither. using 15 years old deprecated methods. if want go fast, need pdo prepared statements. @alberto right. pretty sure, can have 1 , sql perform here way might want consider in case off:

$showerror = true;  define("sqlhost", "127.0.0.1"); define("sqluser", "login"); define("sqlpass", "password"); define("sqlsgbd", "database");  $conn = new pdo('mysql:host=' . sqlhost . ';dbname=' . sqlsgbd . ';charset=utf8', sqluser, sqlpass); $conn->setattribute(pdo::attr_errmode, pdo::errmode_exception); $sql1 = 'select * members order id asc'; $stmt1 = $conn->prepare($sql1); $sql2 = 'select * photos member in ? order id asc'; $stmt2 = $conn->prepare($sql2);  try {     $stmt1->execute();     $members = $stmt1->fetchall(pdo::fetch_assoc); } catch (pdoexception $e) {     if ($showerror === true) {         var_dump("error query 1:" . __line__ . "-------" . __function__ . "-------" . $e->getmessage());         exit;     } }  if (count($members) !== 0) {     $memberids = array();     foreach ($members $m) {         $memberids[] = $m['id'];     }     $memberlist = join(',', $memberids);      foreach ($members $memberarraykey => $result1) {         $stmt2->bindparam(1, $memberlist, pdo::param_str);         try {             $stmt2->execute();             $photos = $stmt2->fetchall(pdo::fetch_assoc);         } catch (pdoexception $e) {             if ($showerror === true) {                 var_dump("error query 2:" . __line__ . "-------" . __function__ . "-------" . $e->getmessage());                 exit;             }         }         if (count($photos) !== 0) {             $memberarraykey = multi_arr_search($p['member'], 'id', $members);             $members[$memberarraykey]['photos'][] = $p;         }     } }