diff --git a/ladybug/sql.py b/ladybug/sql.py
index e6bc8471..dc185812 100644
--- a/ladybug/sql.py
+++ b/ladybug/sql.py
@@ -421,6 +421,7 @@ def data_collections_by_output_name_run_period(self, output_name, run_period_ind
 
             # extract all data of the relevant type from ReportData
             rel_indices = tuple(row[0] for row in header_rows)
+            rel_indices = str(rel_indices).replace(',)', ')')
             query = 'SELECT ReportData.Value, ReportData.TimeIndex ' \
                 'FROM ReportData ' \
                 'INNER JOIN Time ON ReportData.TimeIndex=Time.TimeIndex ' \