ST_GEOMETRYN

База данных: MySQL

68747470733a2f2f7374796c65732e7265646469746d656469612e636f6d2f74355f32716d366b2f7374796c65

ST_GeometryN(gc, N)

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

ST_GeometryN() handles its arguments as described in the introduction
to this section.

URL: https://dev.mysql.com/doc/refman/8.0/en/gis-geometrycollection-property-functions.html

Example

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) |
+-------------------------------------------------+