SQL Exercises: Different grades than other Dallas customers

SQL SUBQUERY : Exercise-30 with Solution

30. From the following tables write a SQL query to find all those customers who have different grades than any customer who lives in Dallas City. Return customer_id, cust_name,city, grade and salesman_id.

customer_id  cust_name     city        grade       salesman_id
-----------  ------------  ----------  ----------  -----------
3002         Nick Rimando  New York    100         5001
3005         Graham Zusi   California  200         5002
3001         Brad Guzan    London      100         5005
3004         Fabian Johns  Paris       300         5006
3007         Brad Davis    New York    200         5001
3009         Geoff Camero  Berlin      100         5003
3008         Julian Green  London      300         5002
3003         Jozy Altidor  Moncow      200         5007

Sample Solution:

-- Selecting all columns from the 'customer' table
SELECT *
-- Specifying the table to retrieve data from ('customer')
FROM customer 
-- Filtering the results based on the condition that 'grade' is not equal to any value in the set of 'grade' values returned by a subquery
WHERE NOT grade = ANY
   -- Subquery: Selecting 'grade' values from the 'customer' table where 'city' is 'Dallas'
   (SELECT grade
	FROM customer
	WHERE city='Dallas');

Output of the Query:

customer_id	cust_name		city		grade	salesman_id
3002		Nick Rimando		New York	100	5001
3007		Brad Davis		New York	200	5001
3005		Graham Zusi		California	200	5002
3008		Julian Green		London		300	5002
3004		Fabian Johnson		Paris		300	5006
3009		Geoff Cameron		Berlin		100	5003
3003		Jozy Altidor		Moscow		200	5007
3001		Brad Guzan		London			5005

Explanation:

The above SQL query is selecting all columns and rows from the 'customer' table where the grade is not equal to any of the grades found in the subquery. The subquery is selecting the grade from the 'customer' table where the city is equal to 'Dallas'. So the main query is getting the rows of all customers whose grade is not equal to any grade of customers living in Dallas.

Visual Explanation:

Practice Online

Sample Database: inventory

Query Visualization:

Duration:

Rows:

Cost:

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