os.system("LD_LIBRARY_PATH=/usr/lib taos -s 'flush database test '")
# os.system(f"LD_LIBRARY_PATH=/usr/lib taos -s 'use test;create stream current_stream into current_stream_output_stb as select _wstart as `start`, _wend as wend, max(current) as max_current from meters where voltage <= 220 interval (5s);' ")
# os.system('LD_LIBRARY_PATH=/usr/lib taos -s "use test;create stream power_stream into power_stream_output_stb as select ts, concat_ws(\\".\\", location, tbname) as meter_location, current*voltage*cos(phase) as active_power, current*voltage*sin(phase) as reactive_power from meters partition by tbname;" ')