MySQL LOG2() function

In this context, we will learn how we can use the MySQL LOG2() function to calculate the Logarithm of a specific number with base 2 with proper syntax and examples.

Introduction of MySQL LOG2() function

LOG2() function in MySQL is used to calculate the natural Logarithm of a specific number with base 2. The number must be >0. Otherwise, it will return NULL.

Syntax of the MySQL LOG2() function

The syntax of the MySQL LOG2() function is given as follows:

LOG2(Y);

Parameters or arguments used in MySQL LOG2() function:

Only one parameter is accepted by the LOG2() function in MySQL, which is given as follows:

Y: It is the number that we want to calculate the Logarithm of the number. It should be a positive number.

Returns: It will return the natural Logarithm of the given number Y with base 2.

Applications used for LOG2() function:

The LOG2() function can be used in the given below MySQL versions:

• MySQL 5.7
• MySQL 5.6
• MySQL 5.5
• MySQL 5.1
• MySQL 5.0
• MySQL 4.1
• MySQL 4.0
• MySQL 3.23

Examples of MySQL LOG2() function:

Now, we will look into some examples of MySQL LOG2 functions.

Example 1:

Here, we will find the Logarithm of the given number with base 2 using the LOG2() function in MySQL.

SELECT LOG2( 16 ) AS LOG2_Val ;

Output:

LOG2_VAL
4
1 row in set (0.00 sec)

Example 2:

Here, we will find the Logarithm of 0 with base 2 using the LOG2() function in MySQL.

SELECT LOG2(0) AS LOG2_Val ;

Output:

LOG2_VAL
NULL
1 row in set (0.00 sec)

Example 3:

When we require to find the Logarithm value with base 2 of column data, then we can take the help of the LOG2 function. For demonstration, we have created a table named commodity.

CREATE TABLE Commodity
(
    Commodity_id INT AUTO_INCREMENT,  
    Commodity_name VARCHAR(100) NOT NULL,
    Purchasing_price DECIMAL(13,2) NOT NULL,
    Selling_price DECIMAL(13,2) NOT NULL,
    Service_grade Decimal(6,2) NOT NULL,
    PRIMARY KEY(Commodity_id)


);

After that, we will insert some data into the Commodity table:

INSERT INTO Commodity
(Commodity_name, Purchasing_price, Selling_price, Service_grade)
VALUES
    ('Touring Bike,' 2019.00,3009.6,0.89 ) ,
    ('Mountain Bike,' 3019.50,4000.56,1.00 ) ,
    ('Road Bike,' 1019.20 ,2000.56,-0.89 ) ,
    ('Road Bicycle,' 1019.50 ,1500.56,-1.50 ) ,
    ('Racing Bicycle,' 3019.50 ,4000.56,2.00) ;

Now we will the below command that will show all data in the Commodity table :

Select * from Commodity;

Commodity_id	Commodity_name	Purchasing_price	Selling_price	Service_grade
1	Touring Bike	2019.00	3009.60	0.89
2	Mountain Bike	3019.50	4000.56	1.00
3	Road Bike	1019.20	2000.56	-0.89
4	Road Bicycle	1019.50	1500.56	-1.50
5	Racing Bicycle	3019.50	4000.56	2.00

Now, we are going to find the Logarithm values with base 2 for all the records present in the Service_grade column.

        Select
    Commodity_id,  
    Commodity_name,  
    Purchasing_price,  
    Selling_price,  
    Service_grade,
    LOG2(Service_grade) AS GRADELOG2  
        FROM Commodity;

The Output is:

Commodity_id	Commodity_name	Purchasing_price	Selling_price	Service_grade	GRADELOG2
1	Touring Bike	2019.00	3009.60	0.89	-0.16812275880832692
2	Mountain Bike	3019.50	4000.56	1.00	0
3	Road Bike	1019.20	2000.56	-0.89	NULL
4	Road Bicycle	1019.50	1500.56	-1.50	NULL
5	Racing Bicycle	3019.50	4000.5

Summary:

In this context, we have learned how we can use the MySQL LOG2() function to find the Logarithm values with base 2 from given arguments respectively.