addressing @josenavas comments

Author: antgonza

qiita_db/study.py

@@ -440,6 +440,9 @@ def delete(cls, id_):
             sql = "DELETE FROM qiita.investigation_study WHERE study_id = %s"
             qdb.sql_connection.TRN.add(sql, args)
 
+            sql = "DELETE FROM qiita.per_study_tags WHERE study_id = %s"
+            qdb.sql_connection.TRN.add(sql, args)
+
             sql = "DELETE FROM qiita.study WHERE study_id = %s"
             qdb.sql_connection.TRN.add(sql, args)
 

qiita_ware/private_plugin.py

@@ -302,8 +302,6 @@ def delete_study(job):
 
         qdb.metadata_template.sample_template.SampleTemplate.delete(study_id)
 
-        # removing tags
-        study.update_tags(job.user, [])
         qdb.study.Study.delete(study_id)
 
         job._set_status('success')