此代码正在无限期加载：

$answer_articles = $bdd->prepare(
 "SELECT * 
  FROM todo
  LEFT JOIN links_task_text
  ON links_task_text.links_task_text_id_task = todo.ID
  WHERE todo.site = ?");
$answer_articles->execute(array('xxx'));
exit();

当然，这个代码是有效的：

$answer_articles = $bdd->prepare(
 "SELECT * 
  FROM todo
  WHERE site = ?");
$answer_articles->execute(array('xxx'));
exit();

//working and no loading delays

这个代码也在起作用：

$answer_articles = $bdd->prepare(
 "SELECT * FROM todo
  INNER JOIN links_task_text
  ON links_task_text.links_task_text_id_task = todo.ID
  WHERE todo.site = ?");
$answer_articles->execute(array('xxx'));
exit();

//works but it's not what I need
``` `links_task_text.links_task_text_id_task` 以及 `todo.ID` 是int。
我不明白为什么左连接不起作用。一些想法？