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://aws.amazon.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/). 

# H3\$1ToParent
<a name="H3_ToParent-function"></a>

H3\$1ToParent returns the parent H3 cell ID at a specified parent resolution for a given H3 index. For information about H3 indexing, see [H3](spatial-terminology.md#spatial-terminology-h3).

## Syntax
<a name="H3_ToParent-function-syntax"></a>

```
H3_ToParent(index, resolution)
```

## Arguments
<a name="H3_ToParent-function-arguments"></a>

 *index*   
A value of data type `BIGINT` or `VARCHAR` that represents the index of an H3 cell, or an expression that evaluates to one of these data types.

 *resolution*   
A value of data type `INTEGER` or an expression that evaluates to an `INTEGER` type. The value represents the resolution of the parent cell ID. The value must be between 0 and the resolution of *index*, inclusive.

## Return type
<a name="H3_ToParent-function-return"></a>

`BIGINT` – represents the parent's H3 cell ID.

If either *index* or *resolution* is NULL, then NULL is returned.

If *index* is not valid, then an error is returned.

If *resolution* is less than 0 or greater than the resolution of *index*, then an error is returned.

## Examples
<a name="H3_ToParent-function-examples"></a>

The following SQL inputs a VARCHAR that represents the index of an H3 cell, and an INTEGER that represents the desired resolution of the desired parent, and returns a BIGINT that represents the parent at resolution 0 of the input H3 cell.

```
SELECT H3_ToParent('85283473fffffff', 0);
```

```
 h3_toparent
--------------------
 577199624117288959
```

The following SQL inputs a BIGINT that represents the index of an H3 cell, and an INTEGER that represents the desired resolution of the desired parent, and returns a BIGINT that represents the parent at resolution 0 of the input H3 cell.

```
SELECT H3_ToParent(646078419604526808, 8);
```

```
 h3_toparent
--------------------
 614553222213795839
```