log function

The log function returns the logarithmic value with the specified base for the given expression.

Syntax:

double log(n,b)

Semantics:

• n, b: The arguments n and b are expressions that resolve to numbers. The base b can resolve to any positive value except zero and one. n can resolve to any positive value.

• return type: double.

  • Returns a NULL value in the following cases:

    • If either of the arguments resolves to a NULL value

    • If either of the arguments does not resolve to a number

  • Returns positive infinity if either of the arguments resolves to positive infinity.

Example 1 - log function

SELECT log(n,b) FROM PHtable

Value of n	Value of b	Output
2	2	1.0
81	3	4.0
255	5	3.442980622208573