What are comparison operators in SQL?

Imagine you’re managing a bookstore and would like to analyze your sales data to make informed decisions about inventory and promotions. SQL comparison operators can help you with this task by allowing you to filter, sort, and analyze the data in a variety of ways. 

Equals (=)

Question: Which books were sold exactly 10 times in the past month?

Example query: 

In this query, the equals (=) operator compares the value in the “sales_last_month” column to 10. The query returns the title and author of books with exactly 10 sales in the past month. 

 

Not Equals (<> or !=)

Question: Which books were sold more or less than 10 times in the past month?

Example query: 

The not equals (<> or !=) operator filters out books with sales equal to 10 in the past month. The query returns the title and author of books with sales not equal to 10. 

 

Greater Than ( > )

Question: Which books sold more than 50 copies in the past month? 

Example query: 

The greater than ( > ) operator compares the “sales_last_month” column to 50. The query returns the title and author of books with sales greater than 50 in the past month. 

 

Less Than (<)

Question: Which books sold fewer than 5 copies in the past month?

Example query: 

The less than (<) operator compares the “sales_last_month” column to 5. The query returns the title and author of books with sales less than 5 in the past month. 

 

Greater Than or Equal To (>=)

Question: Which books sold at least 20 copies in the past month?

Example query: 

The greater than or equal to (>=) operator filters books based on a minimum sales value. The query returns the title and author of books with sales equal to or greater than 20 in the past month. 

 

Less Than or Equal To (<=)

Question: Which books sold no more than 30 copies in the past month?  

Example query: 

 

The less than or equal to (<=) operator filters books based on a maximum sales value. The query returns the title and author of books with sales equal to or less than 30 in the past month. 

 

By utilizing these comparison operators in SQL, you can easily filter and analyze your bookstore’s sales data to make informed decisions and optimize your business.