如何解码存储在数据库中的数组的foreach值

How to decode foreach value of array stored in database

这是print_r($query->getResult()):

Array ( [0] => stdClass Object ( [id] => 9
                                 [user_id] =>
                                 [title] =>
                                 [message] => [{"title":"Nice","option":"Text 1"},{"title":"nice 2","option":"text 2"},{"title":"nice 3","option":"text 3"}]
                                 [created_at] => 2020-06-21 16:59:49
               )
)

我正在尝试使用以下方式回应它:

$query = $db->query("SELECT * from user_msg");

foreach (json_decode($query->getResult()) as $key => $additional_field) {
 
echo $additional_field->title;

}

但不幸的是我得到了这个错误:

json_decode() expects parameter 1 to be string, array given

我不知道 CodeIgnitor,但是根据结果数组和 JSON,你需要做这样的事情:

foreach ($query->getResult() as $row) {
    foreach(json_decode($row->message) as $msg) {
        echo $msg->title;
    }   
}

循环结果中的每一行,解码 message 并循环得到 titles。