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    Lindorm:Accessor functions

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    Lindorm:Accessor functions

    Last Updated:Mar 30, 2026

    The Lindorm GanosBase access functions retrieve geometric properties from spatial data, including points, coordinate values, bounding box extents, and vertex counts. These functions apply to LindormTable with no version requirements.

    Function list

    Function Description
    ST_Centroid Returns the centroid of a Geometry object
    ST_EndPoint Returns the last point of a LineString
    ST_NPoints Returns the number of vertices in a Geometry object
    ST_StartPoint Returns the start point of a LineString
    ST_X Returns the X-coordinate value of a Point
    ST_XMax Returns the maximum X-coordinate of the bounding box of a Geometry object
    ST_XMin Returns the minimum X-coordinate of the bounding box of a Geometry object
    ST_Y Returns the Y-coordinate value of a Point
    ST_YMax Returns the maximum Y-coordinate of the bounding box of a Geometry object
    ST_YMin Returns the minimum Y-coordinate of the bounding box of a Geometry object

    ST_Centroid

    Returns the centroid of a Geometry object.

    If the Geometry object is empty, this function returns an empty geometry.

    Syntax

    geometry ST_Centroid(geometry g)

    Parameters

    Parameter Description
    g The input Geometry object

    Examples

    Example 1: Centroid of a point collection

    SELECT ST_AsText(ST_Centroid(ST_Collect(ST_MakePoint(1,1),ST_MakePoint(-1,-1)))) AS astext;

    Result:

    +-------------+
|   astext    |
+-------------+
| POINT (0 0) |
+-------------+

    Example 2: Centroid of a LineString

    SELECT ST_AsText(ST_Centroid(ST_GeomFromText('LINESTRING(0 0,0 1,1 2)'))) AS astext;

    Result:

    +--------------------------------+
|             astext             |
+--------------------------------+
| POINT (0.2928932188134525      |
| 1.085786437626905)             |
+--------------------------------+

    Related functions

    ST_EndPoint, ST_NPoints, ST_StartPoint, ST_X, ST_Y

    ST_EndPoint

    Returns the last point of a LineString.

    Returns NULL if the input is not a LineString.

    Syntax

    geometry ST_EndPoint(geometry g)

    Parameters

    Parameter Description
    g The input Geometry object

    Examples

    Example 1: Last point of a LineString

    SELECT ST_AsText(ST_EndPoint(ST_GEOMFROMTEXT('LINESTRING(1 1, 2 2, 3 3)'))) AS endpoint;

    Result:

    +-------------+
|  endpoint   |
+-------------+
| POINT (3 3) |
+-------------+

    Example 2: Non-LineString input returns NULL

    SELECT ST_EndPoint(ST_GeomFromText('POINT(1 1)')) IS NULL AS is_null;

    Result:

    +---------+
| is_null |
+---------+
| true    |
+---------+

    Related functions

    ST_StartPoint, ST_NPoints

    ST_NPoints

    Returns the number of vertices in a Geometry object. Applies to any geometry type.

    Syntax

    int ST_NPoints(geometry g)

    Parameters

    Parameter Description
    g The input Geometry object

    Example

    SELECT ST_NPoints(ST_GeomFromText('LINESTRING(77.29 29.07,77.42 29.26,77.27 29.31,77.29 29.07)')) AS npoints;

    Result:

    +---------+
| npoints |
+---------+
| 4       |
+---------+

    Related functions

    ST_StartPoint, ST_EndPoint

    ST_StartPoint

    Returns the start point of a LineString.

    Returns NULL if the input is not a LineString.

    Syntax

    geometry ST_StartPoint(geometry g)

    Parameters

    Parameter Description
    g The input Geometry object

    Examples

    Example 1: Start point of a LineString

    SELECT ST_AsText(ST_StartPoint(ST_GEOMFROMTEXT('LINESTRING(0 1, 0 2)'))) AS startpoint;

    Result:

    +-------------+
| startpoint  |
+-------------+
| POINT (0 1) |
+-------------+

    Example 2: Non-LineString input returns NULL

    SELECT ST_StartPoint(ST_GeomFromText('POINT(1 1)')) IS NULL AS is_null;

    Result:

    +---------+
| is_null |
+---------+
| true    |
+---------+

    Related functions

    ST_EndPoint, ST_NPoints

    ST_X

    Returns the X-coordinate value of a Point.

    The input must be of the Point type. Returns NULL if the input is an empty Point or NULL.

    Syntax

    BigDecimal ST_X(geometry a_point)

    Parameters

    Parameter Description
    a_point The input Point object

    Examples

    Example 1: X-coordinate of a Point

    SELECT ST_X(ST_MakePoint(1.0, 2.0)) AS x;

    Result:

    +---+
| x |
+---+
| 1 |
+---+

    Example 2: NULL input returns NULL

    SELECT ST_X(NULL) IS NULL AS is_null;

    Result:

    +---------+
| is_null |
+---------+
| true    |
+---------+

    Related functions

    ST_Y, ST_XMax, ST_XMin

    ST_XMax

    Returns the maximum X-coordinate of the bounding box of a Geometry object.

    Supports Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon, and GeometryCollection. Returns -1 if the Geometry object is empty.

    Syntax

    BigDecimal ST_XMax(geometry g)

    Parameters

    Parameter Description
    g The input Geometry object

    Example

    SELECT ST_XMax(ST_GeomFromText('LINESTRING(1 3,5 6)')) AS xmax;

    Result:

    +------+
| xmax |
+------+
| 5    |
+------+

    Related functions

    ST_XMin, ST_YMax, ST_YMin, ST_X

    ST_XMin

    Returns the minimum X-coordinate of the bounding box of a Geometry object.

    Supports Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon, and GeometryCollection. Returns 0 if the Geometry object is empty.

    Syntax

    BigDecimal ST_XMin(geometry g)

    Parameters

    Parameter Description
    g The input Geometry object

    Example

    SELECT ST_XMin(ST_GeomFromText('LINESTRING(1 3,5 6)')) AS xmin;

    Result:

    +------+
| xmin |
+------+
| 1    |
+------+

    Related functions

    ST_XMax, ST_YMax, ST_YMin, ST_X

    ST_Y

    Returns the Y-coordinate value of a Point.

    The input must be of the Point type. Returns NULL if the input is an empty Point or NULL.

    Syntax

    BigDecimal ST_Y(geometry a_point)

    Parameters

    Parameter Description
    a_point The input Point object

    Examples

    Example 1: Y-coordinate of a Point

    SELECT ST_Y(ST_MakePoint(1.0, 2.0)) AS y;

    Result:

    +---+
| y |
+---+
| 2 |
+---+

    Example 2: NULL input returns NULL

    SELECT ST_Y(NULL) IS NULL AS is_null;

    Result:

    +---------+
| is_null |
+---------+
| true    |
+---------+

    Related functions

    ST_X, ST_YMax, ST_YMin

    ST_YMax

    Returns the maximum Y-coordinate of the bounding box of a Geometry object.

    Supports Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon, and GeometryCollection. Returns -1 if the Geometry object is empty.

    Syntax

    BigDecimal ST_YMax(geometry g)

    Parameters

    Parameter Description
    g The input Geometry object

    Example

    SELECT ST_YMax(ST_GeomFromText('LINESTRING(1 3,5 6)')) AS ymax;

    Result:

    +------+
| ymax |
+------+
| 6    |
+------+

    Related functions

    ST_YMin, ST_XMax, ST_XMin, ST_Y

    ST_YMin

    Returns the minimum Y-coordinate of the bounding box of a Geometry object.

    Supports Point, LineString, Polygon, MultiPoint, MultiLineString, MultiPolygon, and GeometryCollection. Returns 0 if the Geometry object is empty.

    Syntax

    BigDecimal ST_YMin(geometry g)

    Parameters

    Parameter Description
    g The input Geometry object

    Example

    SELECT ST_YMin(ST_GeomFromText('LINESTRING(1 3,5 6)')) AS ymin;

    Result:

    +------+
| ymin |
+------+
| 3    |
+------+

    Related functions

    ST_YMax, ST_XMax, ST_XMin, ST_Y