Oracle Exam 1Z0-071 Topic 9 Question 112 Discussion

In Oracle SQL, when you subtract a number from a date, the result is a date. When you subtract one date from another, the result is the number of days between the two dates.

B: PROMO_BEGIN_DATE - 5 will subtract 5 days from the PROMO_BEGIN_DATE, resulting in a new date that is 5 days earlier than PROMO_BEGIN_DATE.

C: PROMO_BEGIN_DATE - SYSDATE will return the number of days between the PROMO_BEGIN_DATE and the current date (SYSDATE).

The incorrect options are:

A: TONUMBER(PROMO_BEGIN_DATE) - 5 will not return a number because PROMO_BEGIN_DATE is a date, and TONUMBER is not a valid function to convert dates to numbers in Oracle.

D: PROMO_BEGIN_DATE - SYSDATE will not return an error; it will return the number of days between the two dates as explained above.

E: TODATE(PROMO_BEGIN_DATE * 5) will not return a date because PROMO_BEGIN_DATE * 5 is not a valid operation in Oracle SQL as you cannot multiply a date by a number, and TODATE is not a valid function. The correct function name is TO_DATE.

Oracle Documentation on Date Arithmetic: Database SQL Language Reference - Datetime Functions