OCP-1Z0-051-題目解析-第24題

24. Examine the structure proposed for the TRANSACTIONS table: 
name                    Null      Type 
TRANS_ID               NOT NULL NUMBER(6) 
CUST_NAME              NOT NULL VARCHAR2(20) 
CUST_STATUS            NOT NULL VARCHAR2 
TRANS_DATE             NOT NULL DATE 
TRANS_VALIDITY                  INTERVAL DAY TO SECOND 
CUST_CREDIT_VALUE               NUMBER(10) 
Which two statements are true regarding the storage of data in the above table structure? (Choose two.) 
A. The TRANS_DATE column would allow storage of dates only in the dd-mon-yyyy format. 
B. The CUST_CREDIT_VALUE column would allow storage of positive and negative integers. 
C. The TRANS_VALIDITY column would allow storage of a time interval in days, hours, minutes, and seconds. 
D. The CUST_STATUS column would allow storage of data up to the maximum VARCHAR2 size of 4,000 characters. 


Answer: BC 


A: TRANS_DATE欄位只能儲存如dd-mon-yyyy格式的資料。（錯誤，Date資料類型可以精確的秒，如dd-mon-yyyy HH24:MI:SS)
B: CUST_CREDIT_VALUE欄位能儲存正整數和負整數。（正確）
C: TRANS_VALIDITY欄位能儲存包含天、小時、分鐘、秒的時間段（正確）
D: CUST_STATUS 欄位最大能儲存4000個字元。（錯誤，沒有指定最大值，會報錯）


這道題可以參見上道題：http://blog.csdn.net/wjx515628/article/details/35623657