ST_InsertAttr - ApsaraDB RDS

為軌跡增加一個新的屬性。

文法

trajectory ST_InsertAttr(trajectory traj, anyarray arr, text name, integer loc default -1);

傳回值

返回增加屬性後的新軌跡。

參數

參數名稱	描述
traj	原軌跡。
arr	一個數組，包含新增屬性的值。
name	新增屬性的名稱。
loc	新增屬性插入的位置，取值範圍為[-n,n]，n為原有屬性數量。 n為正值時，從0開始，0代表插入到第一列前，n代表插入到第n列後。 n為負值時，代表從右側開始插入，-1代表插入到最後一列之後，-n代表插入到第一列之後。

描述

將一個數組作為一列新屬性插入到軌跡中。

樣本

With traj as (select ST_MakeTrajectory('STPOINT'::leaftype,
                                       st_geomfromtext('LINESTRING (114 35, 115 36, 116 37)', 4326),
                                       '[2010-01-01 14:30, 2010-01-01 15:30)'::tsrange,
                                       '{"leafcount":3,"attributes":{"velocity": {"type": "integer", "length": 2,"nullable" : true,"value": [120, 130, 140]}, "accuracy": {"type": "float", "length": 4, "nullable" : false,"value": [120, 130, 140]}, "bearing": {"type": "float", "length": 8, "nullable" : false,"value": [120, 130, 140]}, "acceleration": {"type": "string", "length": 20, "nullable" : true,"value": ["120", "130", "140"]}, "active": {"type": "timestamp", "nullable" : false,"value": ["Fri Jan 01 14:30:00 2010", "Fri Jan 01 15:00:00 2010", "Fri Jan 01 15:30:00 2010"]}}}') as tj)
SELECT ST_InsertAttr(tj, ARRAY[1, 4, 6], 'add', 3) from traj;

返回結果：

{"trajectory":{"version":1,"type":"STPOINT","leafcount":3,"start_time":"2010-01-01 14:30:00","end_time":"2010-01-01 15:30:00","spatial":"SRID=4326;LINESTRING(114 35,115 36,116 37)","timeline":["2010-01-01 14:30:00","2010-01-01 15:00:00","2010-01-01 15:30:00"],"attributes":{"leafcount":3,"velocity":{"type":"integer","length":2,"nullable":true,"value":[120,130,140]},"accuracy":{"type":"float","length":4,"nullable":false,"value":[120.0,130.0,140.0]},"bearing":{"type":"float","length":8,"nullable":false,"value":[120.0,130.0,140.0]},"add":{"type":"integer","length":4,"nullable":true,"value":[1,4,6]},"acceleration":{"type":"string","length":20,"nullable":true,"value":["120","130","140"]},"active":{"type":"timestamp","length":8,"nullable":false,"value":["2010-01-01 14:30:00","2010-01-01 15:00:00","2010-01-01 15:30:00"]}}}}