GeometryN(gc,N)

ST_GeometryN() and GeometryN() are synonyms. For more information, see the description of ST_GeometryN().

NumGeometries(gc)

ST_NumGeometries() and NumGeometries() are synonyms. For more information, see the description of ST_NumGeometries().

ST_GeometryN(gc,N)

Returns the N-th geometry in the GeometryCollection value gc. Geometries are numbered beginning with 1.

mysql> SET @gc = 'GeometryCollection(Point(1 1),LineString(2 2, 3 3))';
mysql> SELECT ST_AsText(ST_GeometryN(ST_GeomFromText(@gc),1));
+-------------------------------------------------+
| ST_AsText(ST_GeometryN(ST_GeomFromText(@gc),1)) |
+-------------------------------------------------+
| POINT(1 1)                                      |
+-------------------------------------------------+

ST_GeometryN() and GeometryN() are synonyms.

ST_GeometryN() was added in MySQL 5.6.1.

ST_NumGeometries(gc)

Returns the number of geometries in the GeometryCollection value gc.

mysql> SET @gc = 'GeometryCollection(Point(1 1),LineString(2 2, 3 3))';
mysql> SELECT ST_NumGeometries(ST_GeomFromText(@gc));
+----------------------------------------+
| ST_NumGeometries(ST_GeomFromText(@gc)) |
+----------------------------------------+
|                                      2 |
+----------------------------------------+

ST_NumGeometries() and NumGeometries() are synonyms.

ST_NumGeometries() was added in MySQL 5.6.1.