Fix problem, not check None for default value
@@ -56,7 +56,7 @@ class DbStep(IconScoreBase):
self._var_addr.set(v_addr)
elif v_bytes is not None:
self._var_bytes.set(bytes(v_bytes))
- elif v_str is not "":
+ elif v_str is not None:
self._var_str.set(str(v_str))
else:
self._var_int.set(int(v_int))
