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> Reference material for MD5_NUMBER_LOWER64 function

# MD5_NUMBER_LOWER64

Represent the lower 64 bits of the MD5 hash value of the input string as `BIGINT`.

## Syntax

```sql theme={"theme":{"light":"css-variables","dark":"css-variables"}}
MD5_NUMBER_LOWER64(<expression>)
```

## Parameters

| Parameter      | Description                                                             | Supported input type |
| :------------- | :---------------------------------------------------------------------- | :------------------- |
| `<expression>` | The string to calculate the MD5 hash value on and represent as `BIGINT` | `TEXT`               |

## Return Type

`BIGINT`

## Example

The following example represents the username `esimpson` as a `BIGINT`:

<div className="query-window">
  ```
  SELECT MD5_NUMBER_LOWER64('esimpson') AS username;
  ```

  | username <span>Decimal(38, 0)</span> |
  | :----------------------------------- |
  | 624533696996866075                   |

  <p><span>Rows: 1</span><span>Execution time: 5.42ms</span></p>
</div>