Help Center/ Data Lake Insight/ Spark SQL Syntax Reference/ Built-In Functions/ Mathematical Functions/ log
Updated on 2023-10-25 GMT+08:00
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log

This function is used to return the natural logarithm of a given base and exponent.

Syntax

log(DOUBLE base, DOUBLE a)

Parameters

Table 1 Parameters

Parameter

Mandatory

Type

Description

base

Yes

DOUBLE, BIGINT, DECIMAL, or STRING

The value can be a float, integer, or string.

If the value is not of the DOUBLE type, the system will implicitly convert it to the DOUBLE type for calculation.

a

Yes

DOUBLE, BIGINT, DECIMAL, or STRING

The value can be a float, integer, or string.

If the value is not of the DOUBLE type, the system will implicitly convert it to the DOUBLE type for calculation.

Return Values

The return value is of the DOUBLE type.

  • If the value of base or a is NULL, NULL is returned.
  • If the value of base or a is negative or 0, NULL is returned.
  • If the value of base is 1 (would cause a division by zero), NULL is returned.

Example Code

The value 2 is returned.

select log(2, 4);

The value NULL is returned.

select log(2, null);

The value NULL is returned.

select log(null, 4);

Parent topic: Mathematical Functions