LN() function :
It is the function in MySQL is used to calculate the natural logarithm of a specific number with base e . The number must be greater than 0, otherwise it will return NULL.
Syntax :
LN(X)
Parameter :
LN() function accepts one parameter as mentioned above in the syntax and described below as follows.
X – A number whose logarithm value with base e we want to calculate. It should be a positive number.
Returns :
It returns the natural logarithm of given number x with base e.
Example-1 :
The logarithm of the given number with base e using the LN() function.
SELECT LN(1000) AS Ln_Val ;
Output :
LN_VAL |
---|
6.907755278982137 |
Example-2 :
The logarithm of 0 using LN() function.
SELECT LN(0) AS Ln_Val ;
Output :
LN_VAL |
---|
NULL |
Example-3 :
The LN function can also be used to find the logarithmic value with base e 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) );
Inserting into the Product table :
Now inserting some data to the Product table –
INSERT INTO Product(Product_name, Buying_price, Selling_price, Service_grade) VALUES ('Touring Bike', 20000.00, 30050.00, 4.17 ), ('Mountain Bike', 30005.50, 40000.56, 10.00 ), ('Road Bike', 10000.20, 21000.56, -3.59 ), ('Road Bicycle', 15200.50, 18000.00, -0.50 ), ('Racing Bicycle', 30500.50, 45000.00, 3.00) ;
Reading data from table :
Showing all data in Product Table –
Select * from Product;
Output :
PRODUCT_ID | PRODUCT_NAME | BUYING_PRICE | SELLING_PRICE | SERVICE_GRADE |
---|---|---|---|---|
1 | Touring Bike | 20000.00 | 30050.00 | 4.17 |
2 | Mountain Bike | 30005.50 | 40000.56 | 10.00 |
3 | Road Bike | 10000.20 | 21000.56 | -3.59 |
4 | Road Bicycle | 15200.50 | 18000.00 | -0.50 |
5 | Racing Bicycle | 30500.50 | 45000.00 | 3.00 |
Now, we are going to find the logarithmic values with base e for all the records present in the Service_grade column.
Select Product_id, Product_name, Buying_price, Selling_price, Service_grade, LN(Service_grade) AS GRADELOGN FROM Product;
Output :
PRODUCT_ID | PRODUCT_NAME | BUYING_PRICE | SELLING_PRICE | SERVICE_GRADE | GRADELOGN |
---|---|---|---|---|---|
1 | Touring Bike | 20000.00 | 30050.00 | 4.17 | 1.4279160358107101 |
2 | Mountain Bike | 30005.50 | 40000.56 | 10.00 | 2.302585092994046 |
3 | Road Bike | 10000.20 | 21000.56 | -3.59 | NULL |
4 | Road Bicycle | 15200.50 | 18000.00 | -0.50 | NULL |
5 | Racing Bicycle | 30500.50 | 45000.00 | 3.00 | 1.0986122886681098 |