How should this query be done?

What should this query do???
There is a lot of content, each of which belongs to a unique parent class, and the implementation is to sort the parent class according to how much content is contained in each parent class.

It's smarty.

This is the code now.

PHP Code

  
  $db->query ("Tag_list", "select * from ' tag ' ORDER by ' ID ' desc limit");    while ($tag _arr = $db->getarray ("Tag_list")) {        $tag _list[] = $tag _arr;    }    $QF->assign (' tag_list ', $tag _list);

This just takes out the name of the parent class and does not sort by how much content is contained in each parent class, how should it be written??

------Solution--------------------
The hint is not that SQL is wrong. is fopen () inside the path is wrong.

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