【PostGIS】实时坐标-电子围栏-判断-（参考遥想公瑾当年postgres+socket.io+nodejs实时地图应用实践）

CREATE OR REPLACE FUNCTION "public"."process_t_gps"() RETURNS "pg_catalog"."trigger" AS $BODY$ DECLARE rec record; ewith record; BEGIN IF (TG_OP = ‘DELETE‘) THEN --插入的GPS都是4326的经纬度，我们将在3857的谷歌底图上显示数据，发送转换后的3857出去 --select TG_OP TG_OP,OLD.id,ST_AsGeojson(ST_AsText(ST_Transform(OLD.geom,3857))) geom,gid as null into rec; --perform pg_notify(‘gps‘,row_to_json(rec)::text); select TG_OP TG_OP,OLD.id,ST_AsGeojson(ST_AsText(OLD.geom)) geom into rec; perform pg_notify(‘gps‘,row_to_json(rec)::text); --SELECT gid,ST_AsGeojson(ST_AsText(s.geom)) as epg,OLD.id,ST_AsGeojson(ST_AsText(NEW.geom)) as gps FROM eploygon s where st_within( OLD.geom , s.geom) into ewith; --raise notice ‘data:%‘,row_to_json(ewith)::text; --perform pg_notify(‘gpswith‘,row_to_json(ewith)::text); RETURN OLD; ELSIF (TG_OP = ‘UPDATE‘) THEN SELECT gid,ST_AsGeojson(ST_AsText(s.geom)) as epg,NEW.id,ST_AsGeojson(ST_AsText(NEW.geom)) as gps FROM eploygon s where st_within( NEW.geom , s.geom) into ewith; --raise notice ‘data:%‘,row_to_json(ewith)::text; --perform pg_notify(‘gpswith‘,row_to_json(ewith)::text); select TG_OP TG_OP,NEW.id,ST_AsGeojson(ST_AsText(NEW.geom)) geom,null as gid into rec; rec.gid = ewith.gid; raise notice ‘data:%‘,row_to_json(rec)::text; perform pg_notify(‘gps‘,row_to_json(rec)::text); RETURN NEW; ELSIF (TG_OP = ‘INSERT‘) THEN SELECT gid,ST_AsGeojson(ST_AsText(s.geom)) as epg,NEW.id,ST_AsGeojson(ST_AsText(NEW.geom)) as gps FROM eploygon s where st_within( NEW.geom , s.geom) into ewith; --raise notice ‘data:%‘,row_to_json(ewith)::text; --raise notice ‘data:%‘,ewith.gid; --perform pg_notify(‘gpswith‘,row_to_json(ewith)::text); select TG_OP TG_OP,NEW.id,ST_AsGeojson(ST_AsText(NEW.geom)) geom ,null as gid into rec; rec.gid = ewith.gid; raise notice ‘data:%‘,row_to_json(rec)::text; perform pg_notify(‘gps‘,row_to_json(rec)::text); RETURN NEW; END IF; RETURN NULL; END; $BODY$ LANGUAGE plpgsql VOLATILE COST 100

参考来源：https://www.jianshu.com/p/4c075a69ca13?mType=Group

 

 备注：pg触发的事件名称需要小写，否则不会发送，如：perform pg_notify(‘gps‘,row_to_json(rec)::text);  

【PostGIS】实时坐标-电子围栏-判断-（参考遥想公瑾当年postgres+socket.io+nodejs实时地图应用实践）