YashanDB ST_DUMP函数

st_covers::= ST_COVERS "(" geometry1 "," geometry2 ")"

--ST_GEOMFROMTEXT函数会根据给定的WKT和SRID返回一个ST_GEOMETRY数据
SELECT ST_Covers(ST_GeomFromText('POLYGON((2 2, 2 4, 4 4, 4 2, 2 2))'), ST_GeomFromText('POINT(3 3)')) res FROM DUAL;

RES 
-------------------- 
true                
                                          
SELECT ST_Covers(ST_GeomFromText('POINT(3 3)'), ST_GeomFromText('POLYGON((2 2, 2 4, 4 4, 4 2, 2 2))')) res FROM DUAL;

RES 
-------------------- 
false               

SELECT ST_Covers(ST_GeomFromText('POLYGON((2 2, 2 4, 4 4, 4 2, 2 2))'), NULL) res FROM DUAL;

RES 
--------------------