# ST_NumGeometries

## 定义

ST_NumGeometries 采用几何集合，并返回集合中的几何数。

## 语法

```sde.st_numgeometries (mpt1 sde.st_geometry)
sde.st_numgeometries (mln1 sde.st_geometry)
sde.st_numgeometries (mpl1 sde.st_geometry)```

## 示例

Oracle

``````CREATE TABLE sample_numgeom (id integer, geometry sde.st_geometry);

INSERT INTO SAMPLE_NUMGEOM VALUES (
1,
sde.st_multipolygon ('multipolygon (((3 3, 4 6, 5 3, 3 3), (8 24, 9 25, 1 28, 8 24), (13 33, 7 36, 1 40, 10 43, 13 33)))', 0)
);

INSERT INTO SAMPLE_NUMGEOM VALUES (
2,
sde.st_multipoint ('multipoint (1 2, 4 3, 5 6, 7 6, 8 8)', 0)
);

SELECT id, sde.st_numgeometries (geometry) NUM_GEOMS_IN_COLL
FROM SAMPLE_NUMGEOM;

ID          NUM_GEOMS_IN_COLL

1                 3
2                 5
``````

PostgreSQL

``````CREATE TABLE sample_numgeom (id integer, geometry sde.st_geometry);

INSERT INTO sample_numgeom VALUES (
1,
sde.st_multipolygon ('multipolygon (((3 3, 4 6, 5 3, 3 3), (8 24, 9 25, 1 28, 8 24), (13 33, 7 36, 1 40, 10 43, 13 33)))', 0)
);

INSERT INTO sample_numgeom VALUES (
2,
sde.st_multipoint ('multipoint (1 2, 4 3, 5 6, 7 6, 8 8)', 0)
);

SELECT id, sde.st_numgeometries (geometry)
AS "number of geometries"
FROM sample_numgeom;

id          number of geometries

1                 3
2                 5
``````
9/15/2013