现象:

猜测原因:
最新版本的 tdengien system 应该是关键词,导致无法 as。
解决方案:
把 as system 改成另一个名字;
select _wstart as ts, last(cpu_engine) as taosd, last(cpu_system) as system2 from $database.dnodes_info where dnode_ep='$fqdn' and ts >= $from and ts <= $to interval($interval) fill(null)