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.