日本熟妇hd丰满老熟妇,中文字幕一区二区三区在线不卡 ,亚洲成片在线观看,免费女同在线一区二区

AI 助理
備案控制臺
文檔
有獎調研
輸入文檔關鍵字查找
首頁 云數據庫 RDS RDS PostgreSQL數據庫 時空引擎（GanosBase） Trajectory SQL參考 SQL參考手冊 屬性元數據 ST_attrNullable

ST_attrNullable

更新時間：
產品詳情
相關技術圈
我的收藏

獲得軌跡屬性是否允許為空。

語法

bool ST_attrNullable(trajectory traj, integer index) ;
bool ST_attrNullable(trajectory traj, text name) ;

參數

參數名稱

描述

traj

軌跡對象。

i?ndex

索引軌跡項。

name

屬性名稱。

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_attrNullable(a, 'velocity') from traj;
 st_attrnullable 
-----------------
 t
(1 row)

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_attrNullable(a, 1) from traj;
 st_attrnullable 
-----------------
 t
(1 row)