add greentest/clean_db.py

greentest/clean_db.py

+#!/usr/bin/python
+from record_results import get_results_db, sqlite3
+
+if __name__=='__main__':
+    c = sqlite3.connect(get_results_db())
+    c.execute('delete from testresult where changeset glob "*+"')
+    c.commit()
+
+