Amazon Redshift will no longer support the use of Python UDFs after June 30, 2026. We will start enforcing it in phases. For more information on the details of Python end of life and migration options, see the [ blog post ](https://aws.amazon.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/) that was published on June 30, 2025. 

# ST\_AddPoint
<a name="ST_AddPoint-function"></a>

ST\_AddPoint returns a linestring geometry that is the same as the input geometry with a point added. If an index is provided, then the point is added at the index position. If the index is -1 or not provided, then the point is appended to the linestring. 

The index is zero-based. The spatial reference system identifier (SRID) of the result is the same as that of the input geometry. 

The dimension of the returned geometry is the same as that of the *geom1* value. If *geom1* and *geom2* have different dimensions, *geom2* is projected to the dimension of *geom1*.

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

```
ST_AddPoint(geom1, geom2)
```

```
ST_AddPoint(geom1, geom2, index)
```

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

 *geom1*   
A value of data type `GEOMETRY` or an expression that evaluates to a `GEOMETRY` type. The subtype must be `LINESTRING`. 

 *geom2*   
A value of data type `GEOMETRY` or an expression that evaluates to a `GEOMETRY` type. The subtype must be `POINT`. The point can be the empty point.

 *index*   
A value of data type `INTEGER` that represents the position of a zero-based index. 

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

`GEOMETRY` 

If *geom1*, *geom2*, or *index* is null, then null is returned. 

If *geom2* is the empty point, then a copy of *geom1* is returned. 

If *geom1* is not a `LINESTRING`, then an error is returned. 

If *geom2* is not a `POINT`, then an error is returned. 

If *index* is out of range, then an error is returned. Valid values for the index position are -1 or a value between 0 and `ST_NumPoints(geom1)`. 

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

The following SQL adds a point to a linestring to make it a closed linestring. 

```
WITH tmp(g) AS (SELECT ST_GeomFromText('LINESTRING(0 0,10 0,10 10,5 5,0 5)',4326))
SELECT ST_AsEWKT(ST_AddPoint(g, ST_StartPoint(g))) FROM tmp;
```

```
 st_asewkt
------------------------------------------------
 SRID=4326;LINESTRING(0 0,10 0,10 10,5 5,0 5,0 0)
```

The following SQL adds a point to a specific position in a linestring. 

```
WITH tmp(g) AS (SELECT ST_GeomFromText('LINESTRING(0 0,10 0,10 10,5 5,0 5)',4326))
SELECT ST_AsEWKT(ST_AddPoint(g, ST_SetSRID(ST_Point(5, 10), 4326), 3)) FROM tmp;
```

```
 st_asewkt
------------------------------------------------
 SRID=4326;LINESTRING(0 0,10 0,10 10,5 10,5 5,0 5)
```