ST_GeomFromText(wkt[, srid]), ST_GeometryFromText(wkt[, srid])

Constructs a geometry value of any type using its WKT representation
and SRID.

The result is NULL if the geometry argument is NULL or not a
syntactically well-formed geometry, or if the SRID argument is NULL.

URL: http://dev.mysql.com/doc/refman/5.7/en/gis-wkt-functions.html

