# LOG2 Function in SQL

The LOG2 is a numeric function in SQL which returns the natural logarithm of the number to the base 2.

### Syntax of LOG2 Function

In the LOG2 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 LOG2 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 LOG2 function.

### Examples of LOG2 function

Example 1: This example gets the log 2 of 1:

Output:

Logarithm_of_1
0

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

Output:

Logarithm_of_10bybase_2
3.322

Example 3: This example returns the logarithm of 8 by base 2 in the output:

Output:

Logarithm_of_8bybase_2
3

Example 4: This example returns the logarithm of 255 by base 2 in the output:

Output:

Logarithm_of_255bybase_2
7.994

Example 5: This example uses the LOG10 function with the SQL table. In this example, we will create the new table through which we will perform the LOG10 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 LOG2 function with the Product_Quantity column of the above Product_Details table:

This query shows the LOG2 value of id of each product.

Output:

Product_ID LOG2_Value_of_Product_ID
104 6.7
202 7.658
103 6.687
111 6.794
210 7.714
212 7.714
112 6.807

Query 2: The following SELECT query uses the LOG2 function with the Purchasing_Price column of the above Product_Details table:

This query shows the LOG2 value of purchasing price of each product.

Output:

945 9.884
45 5.492
25 4.644
5 2.322
50 5.644
110 6.781
550 9.103

Query 3: The following SELECT query uses the LOG2 function with the Product_Rating column of the above Product_Details table:

This query shows the LOG2 value of rating of each product from the above table.

Output:

Product_Rating LOG2_Value_of_productrating
NULL
5 2.322
4 2
9 3.17
NULL
4 2
NULL

Query 4: The following SELECT query uses the LOG2 function with the and Purchasing_Price and Selling_Price column of the above Product_Details table:

This query shows the LOG2 value of selling price of each product.

Output:

Selling_Price LOG2_Value_of_SellingPrice
NULL
75 6.229
NULL
15 3.907
70 6.129
250 7.966
835 9.706