Mathematical functions: Random number, power, square root

--Mathematical functions
--rand generates a random number between 0~1, which contains 0 but does not contain 1
Select RAND ()
--abs: Absolute Value: Negative value-positive value
Select ABS (-100)
--ceiling (); Gets the smallest integer larger than the current parameter value
Select CEILING (0.00000001)
--floor (): Gets the largest integer smaller than the current number
Select Floor (0.999999)
--power () Power
Select POWER (3,5)
--round (source data, number of decimal digits) rounded. The precision of the decimal place is only followed by a specified number of digits after a
Select ROUND (1.449,1)
--sign Negative-1 positive 1 0 0
sqrt-Square Root
Select SQRT (8) Math function

Mathematical functions: Random number, power, square root