In MariaDB, LOG10()
is a built-in function that returns the base-10 logarithm of its argument.
Syntax
The syntax goes like this:
LOG10(X)
Where X
is the value for which to return the base-10 logarithm.
Example
Here’s an example to demonstrate:
SELECT LOG10(3);
Result:
+---------------------+ | LOG10(3) | +---------------------+ | 0.47712125471966244 | +---------------------+
Here are some more:
SELECT
LOG10(10),
LOG10(100),
LOG10(1000),
LOG10(10000);
Result:
+-----------+------------+-------------+--------------+ | LOG10(10) | LOG10(100) | LOG10(1000) | LOG10(10000) | +-----------+------------+-------------+--------------+ | 1 | 2 | 3 | 4 | +-----------+------------+-------------+--------------+
Argument Ranges
If X
is less than or equal to 0
, then NULL
is returned with a warning.
SELECT
LOG10(0),
LOG10(-2);
Result:
+----------+-----------+ | LOG10(0) | LOG10(-2) | +----------+-----------+ | NULL | NULL | +----------+-----------+ 1 row in set, 2 warnings (0.001 sec)
Let’s check the warnings:
SHOW WARNINGS;
Result:
+---------+------+---------------+ | Level | Code | Message | +---------+------+---------------+ | Warning | 1365 | Division by 0 | | Warning | 1365 | Division by 0 | +---------+------+---------------+
Non-Numeric Arguments
Here’s an example of what happens when we provide non-numeric arguments:
SELECT LOG10('Homer');
Result:
+----------------+ | LOG10('Homer') | +----------------+ | NULL | +----------------+ 1 row in set, 2 warnings (0.000 sec)
Let’s see the warning:
SHOW WARNINGS;
Result:
+---------+------+-------------------------------------------+ | Level | Code | Message | +---------+------+-------------------------------------------+ | Warning | 1292 | Truncated incorrect DOUBLE value: 'Homer' | | Warning | 1365 | Division by 0 | +---------+------+-------------------------------------------+
Null Arguments
LOG10()
returns null
if its argument is null
:
SELECT LOG10(null);
Result:
+-------------+ | LOG10(null) | +-------------+ | NULL | +-------------+
Missing Arguments
Calling LOG10()
with the wrong number of arguments, or without any arguments results in an error:
SELECT LOG10();
Result:
ERROR 1582 (42000): Incorrect parameter count in the call to native function 'LOG10'
And:
SELECT LOG10(10, 2);
Result:
ERROR 1582 (42000): Incorrect parameter count in the call to native function 'LOG10'