You have been given two tables,CUSTOMER and SALE.You want to check the referential integrity constraint: SALE.CustomerNumber must exist in CUSTOMER.CustomerNumber
You run the following SQL query:
SELECT CustomerNumber
FROM SALE
WHERE CustomerNumber NOT IN
(SELECT CustomerNumber
FROM CUSTOMER);
What is shown in the results of this query?
A)All values of CustomerNumber that match the constraint.
B)All values of CustomerNumber that violate the constraint.
C)All values of CustomerNumber where
SALE.CustomerNumber = CUSTOMER.CustomerNumber.
D)All values of Customer number that are in CUSTOMER but not in SALE.

Question

Quizplus · Accepted Answer

The query is selecting all CustomerNumbers from the SALE table that are not present in the CUSTOMER table. This means that it is checking for values that violate the referential integrity constraint, i.e. CustomerNumbers in SALE that do not have a corresponding CustomerNumber in CUSTOMER. Therefore, the result will show all values of CustomerNumber that violate the constraint.

You Have Been Given Two Tables,CUSTOMER and SALE