ST_AsText,ST_AsWKT
description
Syntax
VARCHAR ST_AsText(GEOMETRY geo)
将一个几何图形转化为WKT（Well Known Text）的表示形式
example
mysql> SELECT ST_AsText(ST_Point(24.7, 56.7));
+---------------------------------+
| st_astext(st_point(24.7, 56.7)) |
+---------------------------------+
| POINT (24.7 56.7) |
+---------------------------------+keywords
ST_ASTEXT,ST_ASWKT,ST,ASTEXT,ASWKT