# Geometry Properties

- [BOUNDARY](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/geometry-properties-boundary.md): Synonym for ST\_BOUNDARY. Returns a geometry representing the closure of the combinatorial boundary of the geometry value.
- [DIMENSION](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/dimension.md): Synonym for ST\_DIMENSION. Returns the inherent dimension of a geometry object (0 for Point, 1 for LineString, 2 for Polygon).
- [ENVELOPE](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/geometry-properties-envelope.md): Synonym for ST\_ENVELOPE. Returns the Minimum Bounding Rectangle (MBR) for the given geometry as a Polygon.
- [GeometryN](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/geometry-properties-geometryn.md): Synonym for ST\_GEOMETRYN. Returns the N-th geometry from a GeometryCollection, numbered starting from 1.
- [GeometryType](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/geometry-properties-geometrytype.md): Synonym for ST\_GEOMETRYTYPE. Returns the name of the geometry type (e.g., 'POINT') of the geometry instance.
- [IsClosed](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/isclosed.md): Synonym for ST\_ISCLOSED. Checks if a LineString's start and end points are the same (closed).
- [IsEmpty](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/geometry-properties-isempty.md): Synonym for ST\_ISEMPTY. Checks if a geometry is empty (contains no point sets). Returns 1 if empty, 0 otherwise.
- [IsRing](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/isring.md): Synonym for ST\_ISRING. Checks if a LineString is a ring, meaning it is both closed and simple.
- [IsSimple](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/geometry-properties-issimple.md): Synonym for ST\_ISSIMPLE. Checks if a geometry is simple, meaning it has no anomalous geometric points like self-intersections.
- [NumGeometries](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/geometry-properties-numgeometries.md): Synonym for ST\_NUMGEOMETRIES. Returns the number of geometries contained in a GeometryCollection.
- [SRID](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/geometry-properties-srid.md): Synonym for ST\_SRID. Returns the Spatial Reference Identifier (SRID) integer associated with the geometry.
- [ST\_BOUNDARY](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_boundary.md): Returns the combinatorial boundary of a geometry. For a Polygon, this is the line string defining the boundary.
- [ST\_DIMENSION](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_dimension.md): Returns the inherent dimension of the geometry value. Returns 0 for points, 1 for linear geometries, and 2 for surface geometries.
- [ST\_ENVELOPE](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_envelope.md): Returns the Minimum Bounding Rectangle (MBR) for the geometry value. The result is returned as a Polygon defined by the corner points.
- [ST\_GEOMETRYN](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_geometryn.md): Returns the N-th geometry in a GeometryCollection. Geometries are numbered beginning with 1.
- [ST\_GEOMETRYTYPE](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_geometrytype.md): Returns the name of the geometry type (e.g., 'POINT', 'LINESTRING', 'POLYGON') for the given geometry instance.
- [ST\_ISCLOSED](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_isclosed.md): Returns 1 if the LineString is closed (start and end points are the same), 0 if not, and NULL if the argument is NULL.
- [ST\_ISEMPTY](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_isempty.md): Checks if a geometry is empty. Returns 1 if the geometry contains no points, and 0 otherwise.
- [ST\_IsRing](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_isring.md): Checks if the LineString is a ring. Returns 1 if the LineString is both closed (start equals end) and simple (no self-intersection).
- [ST\_IsSimple](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_issimple.md): Checks if the geometry is simple (no self-intersections or anomalous points). Returns 1 if simple, 0 otherwise.
- [ST\_NUMGEOMETRIES](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_numgeometries.md): Returns the number of geometries in a GeometryCollection. Returns NULL if the argument is not a GeometryCollection.
- [ST\_RELATE](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_relate.md): Tests if two geometries are spatially related according to a given DE-9IM intersection matrix pattern.
- [ST\_SRID](https://mariadb.com/docs/server/reference/sql-statements/geometry-constructors/geometry-properties/st_srid.md): Returns the Spatial Reference Identifier (SRID) for the geometry. This integer represents the coordinate system used.


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