獲得軌跡指定索引事件的類型。
語法
integer ST_eventType(trajectory traj, integer index) ;參數
參數名稱 | 描述 |
traj | 軌跡對象。 |
index | 事件序號。 |
示例
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]},"angel":{"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_eventType(a, 0 ) from traj;
st_eventtype
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