Selecting duplicates posts from one category (SQL) or plugin

Hi everyone!
While I do understand a little SQL syntax, I’m not a big expert, so when advanced stuff comes into the game, I start gasping a bit.

I’m using the following query within, phpMyAdmin, to delete all duplicated posts:

DELETE bad_rows.*
from wp_posts as bad_rows
inner join (
select post_title, MIN(id) as min_id
from wp_posts
group by post_title
having count(*) > 1
) as good_rows on good_rows.post_title = bad_rows.post_title
and good_rows.min_id bad_rows.id

But I would like to modify it, selecting only duplicated records from a given category.

The following basic query, selects all records from a given category:

SELECT * FROM wp_posts
LEFT JOIN wp_term_relationships ON(wp_posts.ID = wp_term_relationships.object_id)
LEFT JOIN wp_term_taxonomy ON(wp_term_relationships.term_taxonomy_id = wp_term_taxonomy.term_taxonomy_id)
WHERE
(wp_term_taxonomy.term_id = 27)
AND wp_term_taxonomy.taxonomy = 'category'

How would you merge the two queries? Maybe with a nested query? Or?

Thanks