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MaxCompute:LOG10

Last Updated:Jul 24, 2023

Calculates the logarithm of number with the base number of 10. This function is an additional function of MaxCompute V2.0.

Syntax

double log10(<number>)

Parameters

number: required. A value of the DOUBLE, BIGINT, INT, SMALLINT, TINYINT, FLOAT, DECIMAL, or STRING type.

Return value

A value of the DOUBLE type is returned. If the value of number is 0, a negative value, or null, null is returned.

Sample data

This section provides sample source data and examples for you to understand how to use the functions. In this topic, a table named mf_math_fun_t is created and data is inserted into the table. Sample statements:

create table if not exists mf_math_fun_t(
     int_data     int,
     bigint_data  bigint,
     double_data  double,
     decimal_data decimal,
     float_data   float,
     string_data  string
    );
insert into mf_math_fun_t values
(null, -10, 0.525, 0.525BD, cast(0.525 as float), '10'),
(-20, null, -0.1, -0.1BD, cast(-0.1 as float), '-10'),
(0, -1, null, 20.45BD, cast(-1 as float), '30'),
(-40, 4, 0.89, null, cast(0.89 as float), '-30'),
(5, -50, -1, -1BD, null, '50'),
(-60, 6, 1.5, 1.5BD, cast(1.5 as float), '-50'),
(-1, -70, -7.5, -7.5BD, cast(-7.5 as float),null ),
(-80, 1, -10.2, -10.2BD, cast(-10.2 as float), '-1' ),
(9, -90, 2.58, 2.58BD, cast(2.58 as float), '0'),
(-100, 10, -5.8, -5.8BD, cast(-5.8 as float), '-90');

Query data from the mf_math_fun_t table. Sample statement:

select * from mf_math_fun_t;
-- The following result is returned: 
+------------+-------------+-------------+--------------+------------+-------------+
| int_data   | bigint_data | double_data | decimal_data | float_data | string_data |
+------------+-------------+-------------+--------------+------------+-------------+
| NULL       | -10         | 0.525       | 0.525        | 0.525      | 10          |
| -20        | NULL        | -0.1        | -0.1         | -0.1       | -10         |
| 0          | -1          | NULL        | 20.45        | -1.0       | 30          |
| -40        | 4           | 0.89        | NULL         | 0.89       | -30         |
| 5          | -50         | -1.0        | -1           | NULL       | 50          |
| -60        | 6           | 1.5         | 1.5          | 1.5        | -50         |
| -1         | -70         | -7.5        | -7.5         | -7.5       | NULL        |
| -80        | 1           | -10.2       | -10.2        | -10.2      | -1          |
| 9          | -90         | 2.58        | 2.58         | 2.58       | 0           |
| -100       | 10          | -5.8        | -5.8         | -5.8       | -90         |
+------------+-------------+-------------+--------------+------------+-------------+

Example: static data

-- The return value is null. 
select log10(null);
-- The return value is null. 
select log10(0);
-- The return value is 0.9030899869919435. 
select log10(8);

Example: table data

Calculate the logarithm of all columns with the base number of 10 based on the Sample data. Sample statement:

-- Enable the MaxCompute V2.0 data type edition. Commit this command along with SQL statements. 
set odps.sql.type.system.odps2=true;
select log10(int_data) as int_new, log10(bigint_data) as bigint_new, log10(double_data) as double_new, log10(decimal_data) as decimal_new, log10(float_data) as float_new, log10(string_data) as string_new from mf_math_fun_t;

The following result is returned:

+--------------------+--------------------+---------------------+---------------------+-----------------------+--------------------+
| int_new            | bigint_new         | double_new          | decimal_new         | float_new             | string_new         |
+--------------------+--------------------+---------------------+---------------------+-----------------------+--------------------+
| NULL               | NULL               | -0.2798406965940431 | -0.2798406965940431 | -0.27984071631668606  | 1.0                |
| NULL               | NULL               | NULL                | NULL                | NULL                  | NULL               |
| NULL               | NULL               | NULL                | 1.3106933123433606  | NULL                  | 1.4771212547196624 |
| NULL               | 0.6020599913279623 | -0.0506099933550872 | NULL                | -0.050610000335573106 | NULL               |
| 0.6989700043360187 | NULL               | NULL                | NULL                | NULL                  | 1.6989700043360185 |
| NULL               | 0.7781512503836435 | 0.17609125905568124 | 0.17609125905568124 | 0.17609125905568124   | NULL               |
| NULL               | NULL               | NULL                | NULL                | NULL                  | NULL               |
| NULL               | 0.0                | NULL                | NULL                | NULL                  | NULL               |
| 0.9542425094393249 | NULL               | 0.4116197059632301  | 0.4116197059632301  | 0.411619693120579     | NULL               |
| NULL               | 1.0                | NULL                | NULL                | NULL                  | NULL               |
+--------------------+--------------------+---------------------+---------------------+-----------------------+--------------------+

Related functions

LOG10 is a mathematical function. For more information about functions related to data computing and conversion, see Mathematical functions.