tdengine 小试牛刀

1.tdengine 小试牛刀 

执行 taosBenchmark -y ,系统将自动在数据库test 下创建一张名为
meters的超级表。包含一万张子表。表名从 d0 到d9999;

2.通过taos客户端查询 
#查看超级表。
taos> show stables;
          stable_name           |
=================================
 td_device_device                  |
 td_device_user                    |
 td_device_data                    |
Query OK, 3 row(s) in set (0.002271s)

#_wstart 伪列可以给出每个窗口的开始时间。
select count(1) from test.meters;
taos> select count(1) from test.meters;
       count(1)        |
========================
             100000000 |
Query OK, 1 row(s) in set (0.094996s)

select avg(current),max(voltage),min(phase) from test.meters;
taos> select avg(current),max(voltage),min(phase) from test.meters;
       avg(current)        | max(voltage) |      min(phase)      |
==================================================================
         0.057352868914346 |           18 |           -1.0000000 |
Query OK, 1 row(s) in set (0.195710s)
select avg(current),max(voltage),min(phase) from test.meters where groupid=10;
taos> select avg(current),max(voltage),min(phase) from test.meters where groupid=10;
       avg(current)        | max(voltage) |      min(phase)      |
==================================================================
         0.057273511500205 |           18 |           -1.0000000 |
Query OK, 1 row(s) in set (0.030357s)

#对表d1001 按每10s进行平均值，最大值，和最小值聚合统计。
select _wstart,avg(current),max(voltage),min(phase) from test.d1001 interval(10s) ;
         _wstart         |       avg(current)        | max(voltage) |      min(phase)      |
============================================================================================
 2017-07-14 10:40:00.000 |         0.057676332952455 |           18 |           -0.9998480 |
Query OK, 1 row(s) in set (0.004629s)