> For the complete documentation index, see [llms.txt](https://mariadb.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://mariadb.com/docs/server/reference/sql-functions/numeric-functions/sqrt.md).

# SQRT

## Syntax

```bnf
SQRT(X)
```

## Description

Returns the square root of X. If X is negative, `NULL` is returned.

## Examples

```sql
SELECT SQRT(4);
+---------+
| SQRT(4) |
+---------+
|       2 |
+---------+

SELECT SQRT(20);
+------------------+
| SQRT(20)         |
+------------------+
| 4.47213595499958 |
+------------------+

SELECT SQRT(-16);
+-----------+
| SQRT(-16) |
+-----------+
|      NULL |
+-----------+

SELECT SQRT(1764);
+------------+
| SQRT(1764) |
+------------+
|         42 |
+------------+
```

<sub>*This page is licensed: GPLv2, originally from*</sub> [<sub>*fill\_help\_tables.sql*</sub>](https://github.com/MariaDB/server/blob/main/scripts/fill_help_tables.sql)

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