[docs](function) Add documentation for ST_NumGeometries, ST_NumPoints…

docs-next/sql-manual/sql-functions/scalar-functions/spatial-functions/st-geometries.md

@@ -0,0 +1,131 @@
+---
+{
+    "title": "ST_GEOMETRIES",
+    "language": "en",
+    "description": "Returns an array of sub-geometries from a geometry collection."
+}
+---
+
+## Description
+
+Decomposes a geometry object into an array of its sub-geometries. For collection types (MultiPolygon), it returns each sub-polygon as a separate element in the array. For non-collection types (Point, LineString, Polygon, Circle), it returns a single-element array containing the geometry itself.
+
+## Syntax
+
+```sql
+ST_GEOMETRIES( <shape> )
+```
+
+## Parameters
+
+| Parameter | Description |
+| :--- | :--- |
+| `<shape>` | The input geometry, of type GEOMETRY or VARCHAR (in WKT format) that can be converted to GEOMETRY. |
+
+## Return Value
+
+Returns an `ARRAY<STRING>` where each element is an encoded geometry object that can be used with other spatial functions such as `ST_AsText` or `ST_GeometryType`.
+
+`ST_GEOMETRIES` has the following edge cases:
+-   If the input parameter is `NULL`, returns `NULL`.
+-   If the input parameter cannot be parsed into a valid geometry object, returns `NULL`.
+-   For non-collection types (`POINT`, `LINESTRING`, `POLYGON`, `CIRCLE`), returns a single-element array containing the input geometry.
+-   For `MULTIPOLYGON`, returns an array where each element is one of the sub-polygons.
+-   Array elements can be passed to other spatial functions for further processing.
+
+## Example
+
+**Geometries of a Point (single-element array)**
+```sql
+SELECT ST_AsText(ST_GEOMETRIES(ST_Point(1, 2))[1]);
+```
+```text
++------------------------------------------------+
+| ST_AsText(ST_GEOMETRIES(ST_Point(1, 2))[1])    |
++------------------------------------------------+
+| POINT (1 2)                                    |
++------------------------------------------------+
+```
+
+**Geometries of a Polygon (single-element array)**
+```sql
+SELECT ST_GeometryType(ST_GEOMETRIES(ST_GeometryFromText('POLYGON((0 0, 1 0, 1 1, 0 1, 0 0))'))[1]);
+```
+```text
++----------------------------------------------------------------------------------------------------+
+| ST_GeometryType(ST_GEOMETRIES(ST_GeometryFromText('POLYGON((0 0, 1 0, 1 1, 0 1, 0 0))'))[1])    |
++----------------------------------------------------------------------------------------------------+
+| ST_POLYGON                                                                                         |
++----------------------------------------------------------------------------------------------------+
+```
+
+**Geometries of a MultiPolygon (multiple elements)**
+```sql
+SELECT SIZE(ST_GEOMETRIES(ST_GeometryFromText('MULTIPOLYGON(((0 0, 1 0, 1 1, 0 1, 0 0)),((2 2, 3 2, 3 3, 2 3, 2 2)))')));
+```
+```text
++----------------------------------------------------------------------------------------------------------------------+
+| SIZE(ST_GEOMETRIES(ST_GeometryFromText('MULTIPOLYGON(((0 0, 1 0, 1 1, 0 1, 0 0)),((2 2, 3 2, 3 3, 2 3, 2 2)))))') |
++----------------------------------------------------------------------------------------------------------------------+
+|                                                                                                                    2 |
++----------------------------------------------------------------------------------------------------------------------+
+```
+
+**Accessing individual elements of a MultiPolygon**
+```sql
+SELECT ST_AsText(ST_GEOMETRIES(ST_GeometryFromText('MULTIPOLYGON(((0 0, 1 0, 1 1, 0 1, 0 0)),((2 2, 3 2, 3 3, 2 3, 2 2)))'))[1]);
+```
+```text
++----------------------------------------------------------------------------------------------------------------------------------+
+| ST_AsText(ST_GEOMETRIES(ST_GeometryFromText('MULTIPOLYGON(((0 0, 1 0, 1 1, 0 1, 0 0)),((2 2, 3 2, 3 3, 2 3, 2 2)))'))[1])    |
++----------------------------------------------------------------------------------------------------------------------------------+
+| POLYGON ((1 0, 1 1, 0 1, 0 0, 1 0))                                                                                             |
++----------------------------------------------------------------------------------------------------------------------------------+
+```
+
+```sql
+SELECT ST_AsText(ST_GEOMETRIES(ST_GeometryFromText('MULTIPOLYGON(((0 0, 1 0, 1 1, 0 1, 0 0)),((2 2, 3 2, 3 3, 2 3, 2 2)))'))[2]);
+```
+```text
++----------------------------------------------------------------------------------------------------------------------------------+
+| ST_AsText(ST_GEOMETRIES(ST_GeometryFromText('MULTIPOLYGON(((0 0, 1 0, 1 1, 0 1, 0 0)),((2 2, 3 2, 3 3, 2 3, 2 2)))'))[2])    |
++----------------------------------------------------------------------------------------------------------------------------------+
+| POLYGON ((3 2, 3 3, 2 3, 2 2, 3 2))                                                                                             |
++----------------------------------------------------------------------------------------------------------------------------------+
+```
+
+**Out-of-bound index (Returns NULL)**
+```sql
+SELECT ST_GEOMETRIES(ST_GeometryFromText('MULTIPOLYGON(((0 0, 1 0, 1 1, 0 1, 0 0)),((2 2, 3 2, 3 3, 2 3, 2 2)))'))[3];
+```
+```text
++----------------------------------------------------------------------------------------------------------------------------+
+| ST_GEOMETRIES(ST_GeometryFromText('MULTIPOLYGON(((0 0, 1 0, 1 1, 0 1, 0 0)),((2 2, 3 2, 3 3, 2 3, 2 2)))'))[3]          |
++----------------------------------------------------------------------------------------------------------------------------+
+| NULL                                                                                                                       |
++----------------------------------------------------------------------------------------------------------------------------+
+```
+
+**NULL Parameter**
+```sql
+SELECT ST_GEOMETRIES(NULL);
+```
+```text
++----------------------+
+| ST_GEOMETRIES(NULL)  |
++----------------------+
+| NULL                 |
++----------------------+
+```
+
+**Invalid Parameter (Returns NULL)**
+```sql
+SELECT ST_GEOMETRIES(ST_GeometryFromText('INVALID'));
+```
+```text
++----------------------------------------------------+
+| ST_GEOMETRIES(ST_GeometryFromText('INVALID'))      |
++----------------------------------------------------+
+| NULL                                               |
++----------------------------------------------------+
+```

docs-next/sql-manual/sql-functions/scalar-functions/spatial-functions/st-numgeometries.md

@@ -0,0 +1,107 @@
+---
+{
+    "title": "ST_NUMGEOMETRIES",
+    "language": "en",
+    "description": "Returns the number of geometries in a geometry collection."
+}
+---
+
+## Description
+
+Returns the number of sub-geometries contained in a geometry object. For non-collection types (Point, LineString, Polygon, Circle), it always returns 1. For collection types (MultiPolygon), it returns the number of sub-geometries in the collection.
+
+## Syntax
+
+```sql
+ST_NUMGEOMETRIES( <shape> )
+```
+
+## Parameters
+
+| Parameter | Description |
+| :--- | :--- |
+| `<shape>` | The input geometry, of type GEOMETRY or VARCHAR (in WKT format) that can be converted to GEOMETRY. |
+
+## Return Value
+
+Returns a BIGINT value representing the number of sub-geometries in the geometry object.
+
+`ST_NUMGEOMETRIES` has the following edge cases:
+-   If the input parameter is `NULL`, returns `NULL`.
+-   If the input parameter cannot be parsed into a valid geometry object, returns `NULL`.
+-   For non-collection types (`POINT`, `LINESTRING`, `POLYGON`, `CIRCLE`), always returns `1`.
+-   For `MULTIPOLYGON`, returns the number of polygons in the collection.
+
+## Example
+
+**Number of geometries in a Point**
+```sql
+SELECT ST_NUMGEOMETRIES(ST_Point(1, 2));
+```
+```text
++----------------------------------+
+| ST_NUMGEOMETRIES(ST_Point(1, 2)) |
++----------------------------------+
+|                                1 |
++----------------------------------+
+```
+
+**Number of geometries in a Polygon**
+```sql
+SELECT ST_NUMGEOMETRIES(ST_GeometryFromText('POLYGON((0 0, 1 0, 1 1, 0 1, 0 0))'));
+```
+```text
++------------------------------------------------------------------------------+
+| ST_NUMGEOMETRIES(ST_GeometryFromText('POLYGON((0 0, 1 0, 1 1, 0 1, 0 0))')) |
++------------------------------------------------------------------------------+
+|                                                                            1 |
++------------------------------------------------------------------------------+
+```
+
+**Number of geometries in a MultiPolygon with two polygons**
+```sql
+SELECT ST_NUMGEOMETRIES(ST_GeometryFromText('MULTIPOLYGON(((0 0, 1 0, 1 1, 0 1, 0 0)),((2 2, 3 2, 3 3, 2 3, 2 2)))'));
+```
+```text
++------------------------------------------------------------------------------------------------------------------+
+| ST_NUMGEOMETRIES(ST_GeometryFromText('MULTIPOLYGON(((0 0, 1 0, 1 1, 0 1, 0 0)),((2 2, 3 2, 3 3, 2 3, 2 2)))')) |
++------------------------------------------------------------------------------------------------------------------+
+|                                                                                                                2 |
++------------------------------------------------------------------------------------------------------------------+
+```
+
+**Number of geometries in a Circle**
+```sql
+SELECT ST_NUMGEOMETRIES(ST_Circle(0, 0, 100));
+```
+```text
++----------------------------------------+
+| ST_NUMGEOMETRIES(ST_Circle(0, 0, 100)) |
++----------------------------------------+
+|                                      1 |
++----------------------------------------+
+```
+
+**NULL Parameter**
+```sql
+SELECT ST_NUMGEOMETRIES(NULL);
+```
+```text
++------------------------+
+| ST_NUMGEOMETRIES(NULL) |
++------------------------+
+|                   NULL |
++------------------------+
+```
+
+**Invalid Parameter (Returns NULL)**
+```sql
+SELECT ST_NUMGEOMETRIES(ST_GeometryFromText('INVALID'));
+```
+```text
++--------------------------------------------------+
+| ST_NUMGEOMETRIES(ST_GeometryFromText('INVALID')) |
++--------------------------------------------------+
+|                                             NULL |
++--------------------------------------------------+
+```

docs-next/sql-manual/sql-functions/scalar-functions/spatial-functions/st-numpoints.md

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+---
+{
+    "title": "ST_NUMPOINTS",
+    "language": "en",
+    "description": "Returns the total number of points in a geometry object."
+}
+---
+
+## Description
+
+Returns the total number of vertices (points) in a geometry object. For different geometry types, the counting rules are as follows: a Point returns 1, a LineString returns the number of vertices, a Polygon returns the total number of vertices across all rings (including the closing point), and a MultiPolygon returns the sum of all sub-polygon point counts.
+
+## Syntax
+
+```sql
+ST_NUMPOINTS( <shape> )
+```
+
+## Parameters
+
+| Parameter | Description |
+| :--- | :--- |
+| `<shape>` | The input geometry, of type GEOMETRY or VARCHAR (in WKT format) that can be converted to GEOMETRY. |
+
+## Return Value
+
+Returns a BIGINT value representing the total number of points in the geometry object.
+
+`ST_NUMPOINTS` has the following edge cases:
+-   If the input parameter is `NULL`, returns `NULL`.
+-   If the input parameter cannot be parsed into a valid geometry object, returns `NULL`.
+-   For `POINT`, returns `1`.
+-   For `LINESTRING`, returns the number of vertices in the line.
+-   For `POLYGON`, returns the total number of vertices across all rings (exterior ring + interior rings). Each ring includes the closing point.
+-   For `MULTIPOLYGON`, returns the sum of point counts of all sub-polygons.
+-   For `CIRCLE`, returns `-1` (circles do not have discrete vertices).
+
+## Example
+
+**Number of points in a Point**
+```sql
+SELECT ST_NUMPOINTS(ST_Point(1, 2));
+```
+```text
++------------------------------+
+| ST_NUMPOINTS(ST_Point(1, 2)) |
++------------------------------+
+|                            1 |
++------------------------------+
+```
+
+**Number of points in a LineString**
+```sql
+SELECT ST_NUMPOINTS(ST_GeometryFromText('LINESTRING(0 0, 1 1, 2 2)'));
+```
+```text
++-------------------------------------------------------------------+
+| ST_NUMPOINTS(ST_GeometryFromText('LINESTRING(0 0, 1 1, 2 2)'))   |
++-------------------------------------------------------------------+
+|                                                                 3 |
++-------------------------------------------------------------------+
+```
+
+**Number of points in a Polygon (square)**
+```sql
+SELECT ST_NUMPOINTS(ST_GeometryFromText('POLYGON((0 0, 1 0, 1 1, 0 1, 0 0))'));
+```
+```text
++----------------------------------------------------------------------------+
+| ST_NUMPOINTS(ST_GeometryFromText('POLYGON((0 0, 1 0, 1 1, 0 1, 0 0))'))  |
++----------------------------------------------------------------------------+
+|                                                                          5 |
++----------------------------------------------------------------------------+
+```
+
+**Number of points in a Polygon with a hole**
+```sql
+SELECT ST_NUMPOINTS(ST_GeometryFromText('POLYGON((0 0, 10 0, 10 10, 0 10, 0 0),(1 1, 2 1, 2 2, 1 2, 1 1))'));
+```
+```text
++-----------------------------------------------------------------------------------------------------------+
+| ST_NUMPOINTS(ST_GeometryFromText('POLYGON((0 0, 10 0, 10 10, 0 10, 0 0),(1 1, 2 1, 2 2, 1 2, 1 1))'))   |
++-----------------------------------------------------------------------------------------------------------+
+|                                                                                                        10 |
++-----------------------------------------------------------------------------------------------------------+
+```
+
+**Number of points in a MultiPolygon**
+```sql
+SELECT ST_NUMPOINTS(ST_GeometryFromText('MULTIPOLYGON(((0 0, 1 0, 1 1, 0 1, 0 0)),((2 2, 3 2, 3 3, 2 3, 2 2)))'));
+```
+```text
++--------------------------------------------------------------------------------------------------------------+
+| ST_NUMPOINTS(ST_GeometryFromText('MULTIPOLYGON(((0 0, 1 0, 1 1, 0 1, 0 0)),((2 2, 3 2, 3 3, 2 3, 2 2)))')) |
++--------------------------------------------------------------------------------------------------------------+
+|                                                                                                           10 |
++--------------------------------------------------------------------------------------------------------------+
+```
+
+**Number of points in a Circle (returns -1)**
+```sql
+SELECT ST_NUMPOINTS(ST_Circle(0, 0, 100));
+```
+```text
++--------------------------------------+
+| ST_NUMPOINTS(ST_Circle(0, 0, 100))  |
++--------------------------------------+
+|                                   -1 |
++--------------------------------------+
+```
+
+**NULL Parameter**
+```sql
+SELECT ST_NUMPOINTS(NULL);
+```
+```text
++---------------------+
+| ST_NUMPOINTS(NULL)  |
++---------------------+
+|                NULL |
++---------------------+
+```
+
+**Invalid Parameter (Returns NULL)**
+```sql
+SELECT ST_NUMPOINTS(ST_GeometryFromText('INVALID'));
+```
+```text
++------------------------------------------------+
+| ST_NUMPOINTS(ST_GeometryFromText('INVALID'))   |
++------------------------------------------------+
+|                                           NULL |
++------------------------------------------------+
+```