Merge pull request #1158 from josenavas/fix-1151

Fixes #1151

Author: antgonza

qiita_db/metadata_template/base_metadata_template.py

@@ -707,9 +707,9 @@ def _add_common_extend_steps_to_queue(self, md_template, conn_handler,
 
             if existing_samples:
                 warnings.warn(
-                    "No values have been modified for samples '%s'. However, "
-                    "the following columns have been added to them: '%s'"
-                    % (", ".join(existing_samples), ", ".join(new_cols)),
+                    "No values have been modified for existing samples (%s). "
+                    "However, the following columns have been added to them: "
+                    "'%s'" % (len(existing_samples), ", ".join(new_cols)),
                     QiitaDBWarning)
                 # The values for the new columns are the only ones that get
                 # added to the database. None of the existing values will be
@@ -731,8 +731,8 @@ def _add_common_extend_steps_to_queue(self, md_template, conn_handler,
                 conn_handler.add_to_queue(queue_name, sql, values, many=True)
         elif existing_samples:
             warnings.warn(
-                "The following samples already exist in the template and "
-                "will be ignored: %s" % ", ".join(existing_samples),
+                "%d samples already exist in the template and "
+                "their values won't be modified" % len(existing_samples),
                 QiitaDBWarning)
 
         if new_samples: