12.16.6 Geometry Format Conversion Functions

MySQL supports the functions listed in this section for converting geometry values from internal geometry format to WKT or WKB format.

There are also functions to convert a string from WKT or WKB format to internal geometry format. See Section 12.16.3, “Functions That Create Geometry Values from WKT Values”, and Section 12.16.4, “Functions That Create Geometry Values from WKB Values”.

• AsBinary(g), AsWKB(g)

  ST_AsBinary(), ST_AsWKB(), AsBinary(), and AsWKB() are synonyms. For more information, see the description of ST_AsBinary().

  AsBinary() and AsWKB() are deprecated; expect them to be removed in a future MySQL release. Use ST_AsBinary() and ST_AsWKB() instead.

• AsText(g), AsWKT(g)

  ST_AsText(), ST_AsWKT(), AsText(), and AsWKT() are synonyms. For more information, see the description of ST_AsText().

  AsText() and AsWKT() are deprecated; expect them to be removed in a future MySQL release. Use ST_AsText() and ST_AsWKT() instead.

• ST_AsBinary(g), ST_AsWKB(g)

  Converts a value in internal geometry format to its WKB representation and returns the binary result.

  If the argument is NULL, the return value is NULL. If the argument is not a syntactically well-formed geometry, an ER_GIS_INVALID_DATA error occurs.

  SELECT ST_AsBinary(g) FROM geom;

  ST_AsBinary(), ST_AsWKB(), AsBinary(), and AsWKB() are synonyms.

• ST_AsText(g), ST_AsWKT(g)

  Converts a value in internal geometry format to its WKT representation and returns the string result.

  If the argument is NULL, the return value is NULL. If the argument is not a syntactically well-formed geometry, an ER_GIS_INVALID_DATA error occurs.

  mysql> SET @g = 'LineString(1 1,2 2,3 3)';
  mysql> SELECT ST_AsText(ST_GeomFromText(@g));
  +--------------------------------+
  | ST_AsText(ST_GeomFromText(@g)) |
  +--------------------------------+
  | LINESTRING(1 1,2 2,3 3)        |
  +--------------------------------+

  ST_AsText(), ST_AsWKT(), AsText(), and AsWKT() are synonyms.

  Output for MultiPoint values includes parentheses around each point. For example:

  mysql> SET @mp = 'MULTIPOINT(1 1, 2 2, 3 3)';
  mysql> SELECT ST_AsText(ST_GeomFromText(@mp));
  +---------------------------------+
  | ST_AsText(ST_GeomFromText(@mp)) |
  +---------------------------------+
  | MULTIPOINT((1 1),(2 2),(3 3))   |
  +---------------------------------+