ST_MakePointM — 从X、Y和M值创建点。
geometry ST_MakePointM(
float x, float y, float m)
;
创建具有未知SRID的点。
SELECT ST_AsEWKT( ST_MakePointM(-71.1043443253471, 42.3150676015829, 10) ); st_asewkt ----------------------------------------------- POINTM(-71.1043443253471 42.3150676015829 10)
使用WGS 84大地坐标系中的测量创建点。
SELECT ST_AsEWKT( ST_SetSRID( ST_MakePointM(-71.104, 42.315, 10), 4326)); st_asewkt --------------------------------------------------------- SRID=4326;POINTM(-71.104 42.315 10)
获取创建点的度量值。
SELECT ST_M( ST_MakePointM(-71.104, 42.315, 10) ); result ------- 10