mysql语句
显示aa表里的所有内容：
> select * from aa;
显示aa表里bb=00的数据：
> select * from aa where bb=00;
显示aa表里bb以COM结尾的数据：
> select * from aa where bb like '%COM';
显示aa表里以COM结尾的数据的前5行：
> select * from aa where bb like '%COM' limit 5;
统计个数（或叫行数）：
> select count(*) from aa;
从3个表里抓取需要的信息（服务器名、ip、监控项、报错）：
> select icinga_hosts.display_name,icinga_hosts.address,icinga_services.display_name,icinga_servicestatus.output from icinga.icinga_hosts,icinga.icinga_services,icinga.icinga_servicestatus where icinga_hosts.host_object_id=icinga_services.host_object_id and icinga_services.service_object_id=icinga_servicestatus.service_object_id and icinga_servicestatus.output='CRITICAL - snmpwalk returns no product name (cpqsinfo-mib), wrong device' and icinga_servicestatus.status_update_time like '2017-08-01%';
