需要幫助的分組PHP數組

Question

我有一個MySQL查詢該吐出來的是以下數組：

Array 
(
    [0] => stdClass Object 
     (
      [item1] => foo 0 
      [item2] => bar 0 
      [catid] => 3 
     ) 

    [1] => stdClass Object 
     (
      [item1] => foo 1 
      [item2] => bar 1 
      [catid] => 7 
     ) 

    [2] => stdClass Object 
     (
      [item1] => foo 2 
      [item2] => bar 2 
      [catid] => 10 
     ) 

    [3] => stdClass Object 
     (
      [item1] => foo 3 
      [item2] => bar 3 
      [catid] => 7 
     ) 

) 

我想知道是否有可能按「類別」的陣列，所以不是重複catids，會有一個catid，每個對象都在裏面..如果這有道理的話？所以說catid 7只會出現一次，裏面有兩個item1/item2。

Answer 1

這個怎麼樣？

foreach($results as $result) { 
    $by_category[$result->catid][] = $result; 
} 

print_r($by_category); 

Answer 2

$ret = array(); 
foreach ($array as $value) { 
    foreach ($value as $key => $item) { 
     if ($key == 'catid') continue; 
     $ret[$value['catid']][] = $item; 
    } 
} 

Answer 3

你可以用ouzo goodies做到這一點：

$categories = Arrays::groupBy($results, Functions::extractField('catid')); 

參見：http://ouzo.readthedocs.org/en/latest/utils/arrays.html#groupby