如果数组的id相同，则对数组的值求和

Question

请参阅下表：

项

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"}]

我想回显所有等于id 22的值的总和 我是php和mysql的新手，非常感谢您的帮助，所以请清楚地向我解释一下代码。

这是我发现的，但不起作用：

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

请帮助....谢谢

Answer 1

看起来$ fields是json数据。如果是，那么

试试这个：

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