增加结果判断

dbexport.py

@@ -44,6 +44,7 @@ def export(target, db=None, alive=False, limit=None, path=None, format='csv', sh
     database = Database(db)
     domains = utils.get_domains(target)
     datas = []
+    if domains:
         for domain in domains:
             table_name = domain_to_table(domain)
             rows = database.export_data(table_name, alive, limit)
@@ -55,6 +56,7 @@ def export(target, db=None, alive=False, limit=None, path=None, format='csv', sh
             data = rows.as_dict()
             datas.extend(data)
     database.close()
+    if datas:
         utils.export_all(alive, format, path, datas)