SQRT function - Amazon Redshift

# SQRT function

The SQRT function returns the square root of a numeric value. The square root is a number multiplied by itself to get the given value.

## Syntax

``SQRT (expression)``

## Argument

expression

The expression must have an integer, decimal, or floating-point data type. The expression can include functions. The system might perform implicit type conversions.

## Return type

SQRT returns a DOUBLE PRECISION number.

## Examples

The following example returns the square root of a number.

``````select sqrt(16);

sqrt
---------------
4
``````

The following example performs an implicit type conversion.

``````select sqrt('16');

sqrt
---------------
4
``````

The following example nests functions to perform a more complex task.

``````select sqrt(round(16.4));

sqrt
---------------
4
``````

The following example results in the length of the radius when given the area of a circle. It calculates the radius in inches, for instance, when given the area in square inches. The area in the sample is 20.

``````select sqrt(20/pi());
``````

This returns the value 5.046265044040321.

The following example returns the square root for COMMISSION values from the SALES table. The COMMISSION column is a DECIMAL column. This example shows how you can use the function in a query with more complex conditional logic.

``````select sqrt(commission)
from sales where salesid < 10 order by salesid;

sqrt
------------------
10.4498803820905
3.37638860322683
7.24568837309472
5.1234753829798
...``````

The following query returns the rounded square root for the same set of COMMISSION values.

``````select salesid, commission, round(sqrt(commission))
from sales where salesid < 10 order by salesid;

salesid | commission | round
--------+------------+-------
1 |     109.20 |    10
2 |      11.40 |     3
3 |      52.50 |     7
4 |      26.25 |     5
...``````