Examine this statement:
SELECT student_id, gpa FROM student_grades WHERE gpa > &&value;
You run the statement once, and when prompted you enter a value of 2.0. A report is produced.
What happens when you run the statement a second time?
A.
An error is returned.
B.
You are prompted to enter a new value.
C.
A report is produced that matches the first report produced.
D.
You are asked whether you want a new value or if you want to run the report based on the previous value.
Explanation:
Use the double-ampersand if you want to reuse the variable value without prompting the user each time.
Incorrect answer:
A:
is not an error
B:
&& will not prompt user for second time
D:
&& will not ask the user for new value
Refer: Introduction to Oracle9i: SQL, Oracle University Study Guide, 7-13