SQRT

Functions › Number

Returns the square root of a number.

Syntax

SQRT( <number> )

Arguments

Argument	Description
<number>	A number zero or greater, or text that reads as one.

Returns

Always a float. NULL when <number> is NULL. A negative number fails the query with "cannot take square root of a negative number"; so does text that does not read as a number.

Usage notes

• On a number column the engine runs it in the data store, where a negative number fails the query the same way; on text it runs after the rows are read.
• Guard values that may be negative with CASE or ABS: SQRT(ABS(x)).

Examples

A standard deviation from sums, since stddev is not available:

SELECT o.region,
       SQRT(SUM(o.total * o.total) / COUNT(o.total)
            - (SUM(o.total) / COUNT(o.total)) * (SUM(o.total) / COUNT(o.total))) AS stddev_total
FROM Order o
GROUP BY o.region

region	stddev_total
north	112.4
south	87.9

See also

POWER · ABS