Related Questions By Tags

RelatedQuestionsByTags.sql

/*Source: http://stackoverflow.com/questions/246841/how-to-find-the-records-with-most-common-tags-like-the-related-questions-in-stac */

select qt.question_id, count(*)
from   question_tags qt
where  qt.tag in
( select qt2.tag
  from   question_tags qt2
  where  qt2.question_id = 123
)
group by qt.question_id
order by 2 desc