常用地图坐标系之间的转换(SQL) 大地坐标系2000转EPSG:4326 (WGS84) st_setsrid(geom,4326) EPSG:4326 (WGS84)转EPSG:3857 (Pseudo-Mercator) st_transform(geom,3857) 查询SRID以及用json格式查看地图数据 st_srid(geom) st_astext(geom)