当子类只有@Transient字段时扩展@Entity的最佳方法(The best way to extend an @Entity when the subclass has just a @Transient field besides)

 为什么不修改您的查询以包含与文章一致的标签？ 我不确定这是不是你想要的，但是用逗号连接起来很简单： 
 
SELECT 
   a.id, 
   a.nazwa, 
   a.data, 
   a.wstep, 
   a.imgs, 
   a.zdj,
   GROUP_CONCAT(t.name) all_tags
FROM 
   art a INNER JOIN tagarts ta ON a.id = ta.id INNER JOIN tags t ON t.idt = ta.idt
 WHERE id BETWEEN $end AND $start
 GROUP BY a.id
 ORDER BY a.id desc;
 
 然后在PHP中进行拆分并瞧！ 
 
foreach($rows as $row) {
   foreach(explode(',', $row['all_tags']) as $tag) {
      echo '<a href="somepath/tags?t={$tag}">{$tag}</a>';
   }
}
 
 这比使用一些查询而不是内部foreach要好得多。 
 
 在任何情况下，当您实际尝试在循环中执行这些查询时，所有内容都会中断的说法可能意味着您只是对代码存在一些问题。 尽管如此，即使它起作用，它仍然会很慢。 
 
 但实际上你可能需要一些完全不同的东西，在这种情况下不要杀了我而是别人。 

Why not modifying your query to include tags in line with articles? I'm not sure if this is what you wanted, but it would be simple enough to concatenate it w/ commas:
 
SELECT 
   a.id, 
   a.nazwa, 
   a.data, 
   a.wstep, 
   a.imgs, 
   a.zdj,
   GROUP_CONCAT(t.name) all_tags
FROM 
   art a INNER JOIN tagarts ta ON a.id = ta.id INNER JOIN tags t ON t.idt = ta.idt
 WHERE id BETWEEN $end AND $start
 GROUP BY a.id
 ORDER BY a.id desc;
 
Then do a split in PHP and voila!
 
foreach($rows as $row) {
   foreach(explode(',', $row['all_tags']) as $tag) {
      echo '<a href="somepath/tags?t={$tag}">{$tag}</a>';
   }
}
 
This would be much more preferable than using some query instead of that inner foreach.
 
In any case, your remark that everything breaks when you actually try doing these queries in a loop probably means that you simply have some issues with your code. Still, even if it worked, it would work slow.
 
But you might actually need something completely different, in which case don't kill me but someone else.