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In a database i have some cars that are rented by customers. I want to find the cars that were rented by All Customers, and display their PlateNr. In other words i want to make SQL Division in MySql.
My Database is like this:

Customer

ID,Name
1 , John
2 , Scott

Car

PlateNr,Colour
1111 , red
2222 , black

Rents

ID , PlateNr , Date
1, 1111, 2010-01-01
1, 1111, 2010-02-01
2, 1111, 2010-03-02
2, 2222, 2010-01-02

Following some instructions i have the following query, but it doesn't work to find the car that was rented by all customers (correct result should be Platenr=1111). What is wrong with the query?

SELECT PlateNr
FROM rents as R1
WHERE NOT EXISTS
 (SELECT car.PlateNr 
 FROM car
 WHERE NOT EXISTS
 (SELECT rents.PlateNr
 FROM rents
 WHERE rents.PlateNr=R1.PlateNr));

I would write this query as:

SELECT PlateNr
FROM Rents
GROUP BY PlateNr
HAVING COUNT(DISTINCT ID) = (SELECT COUNT(*) FROM Customer);

In plain English, this says to find all plates whose distinct count of renting customers matches the total number of customers. I assume here that ID is a unique column in the Customers table.

With this query you can see which customer rented which car and how many times, ıf you can ask something else you can add a comment

Select Customer.Name,Car.PlateNr,count(*) as Count
 from Customer inner join Rents On Rents.ID=Customer.ID
 inner join Car On Car.PlateNr=Rents.PlateNr
 group by Customer.Name,Car.PlateNr
 having count(*)>1