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

> Reference material for HASH function

# HASH

Takes one or more input parameters of any data type and returns a 64-bit non-cryptographic hash value. `HASH` uses the CityHash algorithm for string data types, implementation-specific algorithms for other data types, and the CityHash combinator to produce the resulting hash value. `NULL` values of any type get the same fixed value. See [CITY\_HASH](/reference-sql/functions-reference/conditional-and-miscellaneous/city-hash) if `NULL` values should produce `NULL`.

## Syntax

```sql theme={"theme":{"light":"css-variables","dark":"css-variables"}}
HASH(<expression>, [, expression [,...]])
```

## Parameters

| Parameter      | Description                                                      | Supported input types |
| :------------- | :--------------------------------------------------------------- | :-------------------- |
| `<expression>` | An expression that returns any data type that Firebolt supports. | Any                   |

## Return type

`BIGINT`

## Examples

<div className="query-window">
  ```
  SELECT HASH('esimpson', '08-25-2016');
  ```

  | hash <span>long</span> |
  | :--------------------- |
  | -6509667128195191394   |

  <p><span>Rows: 1</span><span>Execution time: 4.85ms</span></p>
</div>

<div className="query-window">
  ```
  SELECT HASH(NULL, '08-25-2016');
  ```

  | hash <span>long</span> |
  | :--------------------- |
  | 7610523868633494549    |

  <p><span>Rows: 1</span><span>Execution time: 7.10ms</span></p>
</div>