如果數組的id相同，則對數組的值求和

Question

請參閱下表：

項目

id  title   fields
1   Dog     [{"id":"11","value":"50"},{"id":"19","value":"100"},{"id":"22","value":"150"}]
2   Cat     [{"id":"19","value":"50"},{"id":"22","value":"100"},{"id":"37","value":"150"}]
3   Bird    [{"id":"14","value":"50"},{"id":"19","value":"100"},{"id":"22","value":"150"}]
4   Mouse   [{"id":"16","value":"50"},{"id":"22","value":"100"},{"id":"34","value":"150"}]
5   Horse   [{"id":"6","value":"50"},{"id":"22","value":"100"},{"id":"47","value":"150"}]

我想要回顯所有等於id 22的值的總和我是php和mysql的完全新手並且會感謝任何幫助，所以請清楚地向我解釋代碼。

這是我發現的，但不起作用：

<?php
    if ($fields->id == 22) {
        $result += $fields['value'];
    }
    return $result;
?>

請幫忙....謝謝

Answer 1

看起來$ fields是json數據。 如果是，那么

嘗試這個：

    $data = json_decode($fields);
    foreach($data as $element) {
      if ($fields->id == 22) {
         $result += intval($fields->value);
      }
    }
    return $result;