SQRT
Returns the square root of a given number, accurate to within the representation of doubles.
Syntax
SQRT ( number )
Arguments
expression: any valid numeric expression.
Return Type
Float or double. If number is is zero, returns 0. If less than 0, returns NULL.
Examples
SELECT SQRT(-2); **** +----------+ | SQRT(-2) | +----------+ | NULL | +----------+
SELECT SQRT(2); **** +--------------------+ | SQRT(2) | +--------------------+ | 1.4142135623730951 | +--------------------+
SELECT SQRT(4); **** +---------+ | SQRT(4) | +---------+ | 2 | +---------+