Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the [ blog post ](https://amazonaws-china.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/). 

# ST\$1NRings
<a name="ST_NRings-function"></a>

ST\$1NRings returns the number of rings in an input geometry. 

## Syntax
<a name="ST_NRings-function-syntax"></a>

```
ST_NRings(geom)
```

## Arguments
<a name="ST_NRings-function-arguments"></a>

 *geom*   
A value of data type `GEOMETRY` or an expression that evaluates to a `GEOMETRY` type.

## Return type
<a name="ST_NRings-function-return"></a>

`INTEGER`

If *geom* is null, then null is returned. 

The values returned are as follows.


| Returned value | Geometry subtype | 
| --- | --- | 
| 0 | Returned if *geom* is a `POINT`, `LINESTRING`, `MULTIPOINT`, or `MULTILINESTRING` subtype  | 
| The number of rings. | Returned if *geom* is a `POLYGON` or `MULTIPOLYGON` subtype | 
| The number of rings in all components | Returned if *geom* is a `GEOMETRYCOLLECTION` subtype | 

## Examples
<a name="ST_NRings-function-examples"></a>

The following SQL returns the number of rings in a multipolygon. 

```
SELECT ST_NRings(ST_GeomFromText('MULTIPOLYGON(((0 0,10 0,0 10,0 0)),((0 0,-10 0,0 -10,0 0)))'));
```

```
 st_nrings
-------------
 2
```