choose two
In the PROMOTIONS table, the PROMO_BEGTN_DATE columm is of datatype DATE and the default date format is DD-MON-RR.
Which two statements are true about expressions using PROMO_BEGIN_DATE contained in a queny?
A) TO_NUMBER(PROMO_ BEGIN_DATE) - 5 will return number
B) TO_DATE(PROMO_BEGIN_DATE * 5) will return a date
C) PROMO_BEGIN_DATE - SYSDATE will return a number.
D) PROMO_BEGIN_DATE - 5 will return a date.
E) PROMO_BEGIN_DATE - SYSDATE will return an error.
Answer：CD
(解析：这道题考的还比较有意义，AAnswer：错是因为日期型的不能转换为 number;日期不能乘除某个数，所以 BAnswer：错;但是日期型的是可以进行加减。)
