ln

This function is used to return the natural logarithm of a given value.

Syntax

ln(DOUBLE a)

Parameters

Table 1 Parameter

Parameter

Mandatory

Type

Description

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.

Note

  • If the value of a is negative or 0, NULL is returned.

  • If the value of a is NULL, NULL is returned.

Example Code

The value 1.144729868791239 is returned.

select ln(3.1415926);

The value 1 is returned.

select ln(2.718281828459045);

The value NULL is returned.

select ln(null);