Su, Xiaomeng 76a5b1ee83 dli_sqlreference_20240227

Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com>
Co-authored-by: Su, Xiaomeng <suxiaomeng1@huawei.com>
Co-committed-by: Su, Xiaomeng <suxiaomeng1@huawei.com>

2024-03-27 22:02:33 +00:00

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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);