> ## Documentation Index
> Fetch the complete documentation index at: https://docs.wherobots.com/llms.txt
> Use this file to discover all available pages before exploring further.

# ST_SRID

Return the spatial reference system identifier (SRID) of the geometry.

## Signatures

```sql theme={"system"}
ST_SRID (A: Geometry)
```

## Parameters

<ParamField body="A" type="Geometry" required>
  The input geometry.
</ParamField>

## Return type

<ResponseField type="Integer">
  An integer value.
</ResponseField>

## Example

```sql theme={"system"}
SELECT ST_SRID(ST_SetSRID(ST_GeomFromWKT('POLYGON((1 1, 8 1, 8 8, 1 8, 1 1))'), 3021))
```

```
3021
```