# LN Function in SQL

The LN is a numeric function in SQL which returns the natural logarithm of the specified integer number.

### Syntax of LN Function

In the LN syntax, we have to pass that decimal number whose log base 2 value we want to find.

In the Structured Query Language, we can also use the LN function with the column of the table as shown in the following block:

In this syntax, we have to define the name and column of that table on which we want to perform the LN function.

### Examples of LN function

Example 1: This example gets the value of log 1:

Output:

Logarithm_of_1
0

Example 2: This example returns the logarithm of 10 in the output:

Output:

Logarithm_of_10
2.302

Example 3: This example returns the logarithm of 8 in the output:

Output:

Logarithm_of_8
2.079

Example 4: This example returns the logarithm of 255 in the output:

Output:

Logarithm_of_255
5.5412

Example 5: This example uses the LN function with the SQL table.

In this example, we will create the new table through which we will perform the LN function on the numeric fields of the table:

The following shows the syntax to create the new table in SQL:

The following CREATE statement creates the Product_Details table for storing the price and quantity of products:

The following multiple INSERT queries insert the records of products with their selling and purchasing price into the Product_Details table:

The following SELECT statement displays the inserted records of the above Product_Details table:

Product_ID Product_Name Product_Quantity Purchasing_Price Selling_Price Release_Date Product_Rating
104 P1 10 945 NULL 2022-04-30 NULL
202 P4 15 45 75 2022-01-28 5
103 P2 18 25 NULL 2022-02-18 4
111 P7 25 5 15 2021-12-25 9
210 P6 15 50 70 2021-10-15 NULL
212 P8 19 110 250 2022-01-28 4
112 P10 10 550 835 2022-04-11 NULL

Query 1: The following SELECT query uses the LN function with the Product_Quantity column of the above Product_Details table:

This query shows the natural logarithm value of id of each product.

Output:

Product_ID LN_Value_of_Product_ID
104 4.6443
202 5.3082
103 4.6347
111 4.7095
210 5.3471
212 5.3565
112 4.7184

Query 2: The following SELECT query uses the LN function with the Purchasing_Price column of the above Product_Details table:

This query shows the natural logarithm value of purchasing price of each product.

Output:

945 6.8511
45 3.8066
25 3.2188
5 1.6094
50 3.912
110 4.7004
550 6.3099

Query 3: The following SELECT query uses the LN function with the Product_Rating column of the above Product_Details table:

This query shows the natural logarithm value of rating of each product from the above table.

Output:

Product_Rating LN_Value_of_productrating
NULL -
5 1.6094
4 1.3862
9 2.1972
NULL -
4 1.3862
NULL -

Query 4: The following SELECT query uses the LN function with the and Purchasing_Price and Selling_Price column of the above Product_Details table:

This query shows the natural logarithm value of selling price of each product.

Output:

Selling_Price LN_Value_of_SellingPrice
NULL -
75 4.317
NULL -
15 2.708
70 4.248
250 5.521
835 6.727