In this article, we are going to cover the LOG2() function that means it will calculate the logarithm of a specific number with base 2.
Pre-requisite :LOG 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 :
LOG2( X )
Parameter :
LOG2() function accepts one parameter which is described below as following.
- X –A number whose logarithm value with base 2 we want to calculate . It should be positive number.
Returns :
It returns the natural logarithm of given number x with base 2.
Example-1 :
Logarithm of given number with base 2 using LOG2() function.
SELECT LOG2(16) AS Log2_Val;
Output :
Log2_Val |
---|
4 |
Example-2 :
Logarithm of 0 using LOG2() function.
SELECT LOG2(0) AS Log2_Val;
Output :
Log2_Val |
---|
NULL |
Example-3 :
The LOG2 function can also be used to find the logarithmic value with base 2 of a column data. To demonstrate create a table named Product.
CREATE TABLE Product ( Product_id INT AUTO_INCREMENT, Product_name VARCHAR(100) NOT NULL, Buying_price DECIMAL(13,2) NOT NULL, Selling_price DECIMAL(13,2) NOT NULL, Service_grade Decimal(6,2) NOT NULL, PRIMARY KEY(Product_id) );
Now inserting some data to the Product table :
INSERT INTO Product (Product_name, Buying_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) ;
Showing all data in Product table :
Select * from Product;
Product_id | Product_name | Buying_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 logarithmic values with base 2 for all the records present in the Service_grade column.
Select Product_id, Product_name, Buying_price, Selling_price, Service_grade, LOG2(Service_grade) AS GRADELOG2 FROM Product;
Output :
Product_id | Product_name | Buying_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 | 4000.56 | 2.00 | 1 |