DELETE a,b,c
FROM
    mahmut.armut_terms AS a
    LEFT JOIN mahmut.armut_term_taxonomy AS c ON a.term_id = c.term_id
    LEFT JOIN mahmut.armut_term_relationships AS b ON b.term_taxonomy_id = c.term_taxonomy_id
WHERE (
    c.taxonomy = 'post_tag' AND c.count = 1
    )