指定轨迹属性字段,根据固定值,过滤出符合条件的轨迹点,返回过滤后的属性字段值(数组)。
语法
1 2 | timestamp[] ST_attrTimestampFilter(trajectory traj, cstring attr_field_name,cstring operator, timestamp value); timestamp[] ST_attrTimestampFilter(trajectory traj, cstring attr_field_name,cstring operator, timestamp value1, timestamp value2); |
参数
参数名称 | 描述 |
---|---|
traj | 轨迹对象。 |
attr_field_name | 指定的属性名称。 |
operator | 过滤符,支持以下字符:
|
value、value1 | 属性固定值、下限。 |
value2 | 属性固定值-上限 |
示例
1 2 3 4 5 6 | insert into traj values( 3 ,ST_makeTrajectory( 'STPOINT' ::leaftype, st_geomfromtext( 'LINESTRING (114 35, 115 36, 116 37)' , 4326 ), ARRAY[ '2010-01-01 14:30' ::timestamp, '2010-01-01 15:00' , '2010-01-01 15:30' ], '{"leafcount": 3, "attributes" : {"heading" : {"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"]}}}' )); select st_attrTimestampFilter(traj, 'heading' , '>' , 'Fri Jan 01 15:00:00 2010' ::timestamp) from traj where id = 3 ; st_attrtimestampfilter ------------------------- { "2010-01-01 15:30:00" } ( 1 row) |