#Oracle quiz

The contact table contains these columns:
First_Name VARCHAR2(25)
Sales_Commission NUMBER(3,2)
Evaluate this SQL statement
SELECT first_name,commission
FROM Contact
WHERE commission= (SELECT Sales_Comission FROM Contact
WHERE UPPER(first_name)= 'Bill')
Which statement below will cause this statement to fail?

A. Bill has a null salescommission resolution.
B. Bill has a zero sales commission resolution.
C. There is no contact with the first name Bill.
D. The first name values in the database are in the lower case.

Answer: [A]
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