属性元数据函数ST_attrDefinition_云数据库 RDS(RDS)-阿里云帮助中心

获得轨迹属性定义。

语法

text ST_attrDefinition(trajectory traj);

参数

参数名称	描述
traj	需要获得属性定义轨迹。

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]}}}}'::trajectory a)
Select st_attrDefinition(a) from traj;
                                                                                                                                      st_attrdefinition                                                                                                                                      
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 {"size":5,"velocity":{"type":"integer","length":4,"nullable":true},"speed":{"type":"float","length":8,"nullable":true},"angel":{"type":"string","length":64,"nullable":true},"tngel2":{"type":"timestamp","length":8,"nullable":true},"bearing":{"type":"bool","length":1,"nullable":true}}
(1 row)