docs/api/sql/Geometry-Accessors/ST_NumInteriorRing.md

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# ST_NumInteriorRing

Introduction: Returns number of interior rings of polygon geometries. It is an alias of [ST_NumInteriorRings](ST_NumInteriorRings.md).

![ST_NumInteriorRing](../../../image/ST_NumInteriorRing/ST_NumInteriorRing.svg "ST_NumInteriorRing")

Format: `ST_NumInteriorRing(geom: Geometry)`

Return type: `Integer`

Since: `v1.6.1`

SQL Example

```sql
SELECT ST_NumInteriorRing(ST_GeomFromText('POLYGON ((0 0, 0 5, 5 5, 5 0, 0 0), (1 1, 2 1, 2 2, 1 2, 1 1))'))
```

Output:

```
1
```