--圆几何构造函数 ST_CreateCircle(geom ,n) geom:为闭合的Polygon,里面必须有个重复的点 n:指定生成圆(椭圆)的坐标个数,不能小于4 drop table if exists dmt; create table dmt(gemo ST_Geometry); insert into dmt (gemo) select dmgeo2.ST_CreateCircle(dmgeo2.ST_GeomFromText('polygon ((0 0, 0 10, 10 10, 10 0, 0 0))'),6) from dual; insert into dmt (gemo) select dmgeo2.ST_CreateCircle(dmgeo2.ST_GeomFromText('polygon ((10 0, 0 10, 10 10, 10 0))'),4) from dual; insert into dmt (gemo) select dmgeo2.ST_CreateCircle(dmgeo2.ST_GeomFromText('polygon ((0 0, 0 10, 10 10,11 11,10 10, 0 0))'),4) from dual; --弧线几何构造函数 ST_CreateArc(geom ,n ,startang ,angextext) startang 表示截取圆弧、椭圆弧线的起始角度 angextent:表示弧线的跨度(由此可得到结束角度),它的取值范围为 0~2*Π,不在此范围内的取值一律视为 2*Π。 返回值:LineString 几何对象。 insert into dmt (gemo) select dmgeo2.ST_CreateArc(dmgeo2.ST_GeomFromText('polygon ((0 0, 0 10, 10 10, 10 0, 0 0))'),6,45,90) -- 扇形几何构造函数 ST_CreateArcPolygon(geom ,n ,startang,angextext ) 返回值:Polygon 几何对象。 insert into dmt (gemo) select dmgeo2.ST_CreateArcPolygon(dmgeo2.ST_GeomFromText('polygon ((0 0, 0 10, 10 10, 10 0, 0 0))'),6,45,90) 圆环几何构造函数ST_CreateAnnulus (geom1,geom2,n) geom1:构建外圆的几何对象。 geom2:构建内圆的几何对象。 n:指定生成圆环的坐标个数 insert into dmt (gemo) select dmgeo2.ST_CreateAnnulus(dmgeo2.ST_GeomFromText('polygon ((0 0, 0 10, 10 10, 10 0, 0 0))'),dmgeo2.ST_GeomFromText('polygon ((10 0, 0 10, 10 10, 10 0))'),6) from dual; 扇环几何构造函数ST_CreateAnnularSector(geom1,geom2,n,startang,angextent) insert into dmt (gemo) select dmgeo2.ST_CreateAnnularSector(dmgeo2.ST_GeomFromText('polygon ((0 0, 0 10, 10 10, 10 0, 0 0))'),dmgeo2.ST_GeomFromText('polygon ((10 0, 0 10, 10 10, 10 0))'),6,20,80) from dual;
标签:10,polygon,dmgeo2,数据类型,ST,学习,GeomFromText,dmt,达梦 From: https://www.cnblogs.com/fangzpa/p/17797101.html