在根据其他博客学习PostGIS时，执行SELECT p1.name,p2.name,ST_Distance_Sphere(p1.the_geom,p2.the_geom) FROM cities AS p1, cities AS p2 WHERE p1.id > p2.id;
一直报错：
ERROR: function sST_Distance_Sphere(geometry, geometry) does not exist
LINE 1: SELECT p1.name,p2.name,st_distance_sphere(p1.the_geom,p2.the...
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
找各种原因：最终发现，可能是版本原因, 将ST_Distance_Sphere改成ST_DistanceSphere就行！