programming-examples/sql/Subqueries/15. Write a query to extract the data from the customer table if and only if one or more of the customers in the customer table are located in London.sql

/*15. Write a query to extract the data from the customer table if and only if one or more of the customers in the customer 
table are located in London.*/
SELECT customer_id,cust_name, city  
FROM customer  
WHERE EXISTS  
   (SELECT *  
    FROM customer   
    WHERE city='London');