iotdb
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Published
20 hours ago •
thulab
thulab
前缀路径聚合问题
IoTDB> select * from root
+-----------------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+
| Time|root.turbine.Shanghai.d2.Energy|root.turbine.Shanghai.d3.Energy| root.turbine.Shanghai.d3.Speed| root.turbine.Beijing.d2.Energy| root.turbine.Beijing.d2.Speed|
+-----------------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+
|2017-12-01T00:22:59.334| null| null| null| 27.928814| 1|
|2017-12-01T00:22:59.855| null| null| null| 25.391584| 0|
|2017-12-01T00:23:00.269| null| null| null| 29.979698| 8|
|2017-12-01T00:23:00.698| null| null| null| 22.309273| 3|
|2017-12-01T00:23:01.117| null| null| null| 29.748756| 11|
|2017-12-01T00:23:01.539| null| null| null| 20.662369| 4|
|2017-12-01T00:23:01.959| null| 23.56449| 6| 26.08468| 4|
|2017-12-01T00:23:02.382| null| 26.359634| 3| 20.690254| 0|
|2017-12-01T00:23:02.795| null| 28.777403| 8| 23.677143| 13|
|2017-12-01T00:23:03.218| null| 27.712833| 3| 20.305994| 5|
|2017-12-01T00:23:03.638| null| 29.470375| 9| 22.673237| 7|
|2017-12-01T00:23:04.060| null| 28.339792| 0| 25.473534| 13|
|2017-12-01T00:23:04.481| null| 20.276184| 5| 26.35075| 10|
|2017-12-01T00:23:04.899| null| 21.032091| 2| 22.565153| 3|
|2017-12-01T00:23:05.317| null| 28.488579| 1| 27.924906| 4|
|2017-12-01T00:23:05.735| null| 28.298925| 8| 28.964344| 7|
|2017-12-01T00:23:06.155| null| 26.81476| 0| 25.271076| 3|
|2017-12-01T00:23:06.575| null| 29.723043| null| 23.091873| 12|
+-----------------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+
record number = 18
execute successfully.
IoTDB> select count(d2) from root.turbine.Shanghai
+-----------------------+--------------------------------------+
| Time|count(root.turbine.Shanghai.d2.Energy)|
+-----------------------+--------------------------------------+
+-----------------------+--------------------------------------+
record number = 0
execute successfully.
IoTDB> select count(d3) from root.turbine.Shanghai
+-----------------------+--------------------------------------+--------------------------------------+
| Time|count(root.turbine.Shanghai.d3.Energy)| count(root.turbine.Shanghai.d3.Speed)|
+-----------------------+--------------------------------------+--------------------------------------+
+-----------------------+--------------------------------------+--------------------------------------+
record number = 0
execute successfully.
IoTDB> select count(d3) from root.turbine.Shanghai
+-----------------------+--------------------------------------+--------------------------------------+
| Time|count(root.turbine.Shanghai.d3.Energy)| count(root.turbine.Shanghai.d3.Speed)|
+-----------------------+--------------------------------------+--------------------------------------+
|1970-01-01T08:00:00.000| 12| 11|
+-----------------------+--------------------------------------+--------------------------------------+
record number = 1
execute successfully.
IoTDB> select count(d2) from root.turbine.Shanghai
+-----------------------+--------------------------------------+
| Time|count(root.turbine.Shanghai.d2.Energy)|
+-----------------------+--------------------------------------+
+-----------------------+--------------------------------------+
record number = 0
execute successfully.
IoTDB> select count(d3) from root.turbine.Shanghai
+-----------------------+--------------------------------------+--------------------------------------+
| Time|count(root.turbine.Shanghai.d3.Energy)| count(root.turbine.Shanghai.d3.Speed)|
+-----------------------+--------------------------------------+--------------------------------------+
+-----------------------+--------------------------------------+--------------------------------------+
record number = 0
execute successfully.
IoTDB> select count(d3) from root.turbine.Shanghai
+-----------------------+--------------------------------------+--------------------------------------+
| Time|count(root.turbine.Shanghai.d3.Energy)| count(root.turbine.Shanghai.d3.Speed)|
+-----------------------+--------------------------------------+--------------------------------------+
|1970-01-01T08:00:00.000| 12| 11|
+-----------------------+--------------------------------------+--------------------------------------+
record number = 1
execute successfully.
在count(d2)之后再做count(d3)才会出问题，单独做count(d3)不会出问题。怀疑因为root.turbine.Shanghai.d2.Energy列为空列，所以count出错。所以向其中插入了一条数据。便没有bug了。
IoTDB> select * from root
+-----------------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+
| Time|root.turbine.Shanghai.d2.Energy|root.turbine.Shanghai.d3.Energy| root.turbine.Shanghai.d3.Speed| root.turbine.Beijing.d2.Energy| root.turbine.Beijing.d2.Speed|
+-----------------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+
|1970-01-01T08:00:12.345| -2000| null| null| null| null|
|2017-12-01T00:22:59.334| null| null| null| 27.928814| 1|
|2017-12-01T00:22:59.855| null| null| null| 25.391584| 0|
|2017-12-01T00:23:00.269| null| null| null| 29.979698| 8|
|2017-12-01T00:23:00.698| null| null| null| 22.309273| 3|
|2017-12-01T00:23:01.117| null| null| null| 29.748756| 11|
|2017-12-01T00:23:01.539| null| null| null| 20.662369| 4|
|2017-12-01T00:23:01.959| null| 23.56449| 6| 26.08468| 4|
|2017-12-01T00:23:02.382| null| 26.359634| 3| 20.690254| 0|
|2017-12-01T00:23:02.795| null| 28.777403| 8| 23.677143| 13|
|2017-12-01T00:23:03.218| null| 27.712833| 3| 20.305994| 5|
|2017-12-01T00:23:03.638| null| 29.470375| 9| 22.673237| 7|
|2017-12-01T00:23:04.060| null| 28.339792| 0| 25.473534| 13|
|2017-12-01T00:23:04.481| null| 20.276184| 5| 26.35075| 10|
|2017-12-01T00:23:04.899| null| 21.032091| 2| 22.565153| 3|
|2017-12-01T00:23:05.317| null| 28.488579| 1| 27.924906| 4|
|2017-12-01T00:23:05.735| null| 28.298925| 8| 28.964344| 7|
|2017-12-01T00:23:06.155| null| 26.81476| 0| 25.271076| 3|
|2017-12-01T00:23:06.575| null| 29.723043| null| 23.091873| 12|
+-----------------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+-------------------------------+
record number = 19
execute successfully.
IoTDB> select count(d2) from root.turbine.Shanghai
+-----------------------+--------------------------------------+
| Time|count(root.turbine.Shanghai.d2.Energy)|
+-----------------------+--------------------------------------+
|1970-01-01T08:00:00.000| 1|
+-----------------------+--------------------------------------+
record number = 1
execute successfully.
IoTDB> select count(d3) from root.turbine.Shanghai
+-----------------------+--------------------------------------+--------------------------------------+
| Time|count(root.turbine.Shanghai.d3.Energy)| count(root.turbine.Shanghai.d3.Speed)|
+-----------------------+--------------------------------------+--------------------------------------+
|1970-01-01T08:00:00.000| 12| 11|
+-----------------------+--------------------------------------+--------------------------------------+
record number = 1
execute successfully.
这个还有些问题，现在不确定对于没有值的列count, max_value到底该输出什么，建议试一下mysql对于没有数据的列max_value, count之类输出什么
这个issue对于普通的聚合已经不存在问题。对于group by的某个切割部分来说如果没有数据的话，count也显示0吗？我认为显示null也是可以的。