ST_eventTimes-AnalyticDB(AnalyticDB)-阿里云帮助中心

Returns the timestamps of all events in a trajectory object as an array.

Syntax

timestamp[] ST_eventTimes(trajectory traj);

Parameters

Parameter	Type	Description
`traj`	trajectory	The trajectory object.

Return value

Returns a timestamp[] array. Each element corresponds to the timestamp of one event in the trajectory.

Example

WITH traj AS (
  SELECT '{"trajectory":{"version":1,"type":"STPOINT","leafcount":2,"start_time":"2010-01-01 11:30:00","end_time":"2010-01-01 12:30:00","spatial":"SRID=4326;LINESTRING(1 1,3 5)","timeline":["2010-01-01 11:30:00","2010-01-01 12:30:00"],"attributes":{"leafcount":2,"velocity":{"type":"integer","length":4,"nullable":true,"value":[1,null]},"speed":{"type":"float","length":8,"nullable":true,"value":[null,1.0]},"angle":{"type":"string","length":64,"nullable":true,"value":["test",null]},"tngel2":{"type":"timestamp","length":8,"nullable":true,"value":["2010-01-01 12:30:00",null]},"bearing":{"type":"bool","length":1,"nullable":true,"value":[null,true]}},"events":[{"1":"Fri Jan 01 14:30:00 2010"},{"2":"Fri Jan 01 14:30:00 2010"}]}}'::trajectory a)
SELECT ST_eventTimes(a) FROM traj;

Output:

               st_eventtimes
-----------------------------------------------
 {"2010-01-01 14:30:00","2010-01-01 14:30:00"}
(1 row)

The trajectory has two events, both at 2010-01-01 14:30:00. ST_eventTimes returns them as a timestamp[] array with one element per event.