LOG() Function in MySQL
Last Updated :
29 Sep, 2020
LOG() function in MySQL is used to calculate the natural logarithm of a specific number. The number must be >0 Otherwise it will return NULL.
Syntax :
LOG(X)
Parameter : This method accepts one parameter as mentioned above and described below :
- X : A number whose logarithm value we want to calculate. It should be positive number.
Returns : It returns the natural logarithm of given number x.
Example-1 : Logarithm of given number using LOG() function.
SELECT LOG(5) AS Log_Val ;
Output :
Log_Val |
1.6094379124341003 |
Example-2 : Logarithm of 0 using LOG() function.
SELECT LOG(0) AS Log_Val ;
Output :
Example-3 : The LOG function can also be used to find the logarithmic value of a column data columns. 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) ;
So, Our table looks like :
mysql> 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 |
+------------+----------------+--------------+---------------+---------------+
5 rows in set (0.00 sec)
Now, we are going to find the logarithmic values for all the records present in the Service_grade column.
Select Product_id,
Product_name,
Buying_price,
Selling_price,
Service_grade,
LOG(Service_grade) AS GRADELOG
FROM Product;
Output :
+------------+----------------+--------------+---------------+---------------+----------------------+
| Product_id | Product_name | Buying_price | Selling_price | Service_grade | GRADELOG |
+------------+----------------+--------------+---------------+---------------+----------------------+
| 1 | Touring Bike | 2019.00 | 3009.60 | 0.89 | -0.11653381625595151 |
| 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 | 0.6931471805599453 |
+------------+----------------+--------------+---------------+---------------+----------------------+
Share your thoughts in the comments
Please Login to comment...