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字段仅仅能存储如dd-mon-yyyy格式的数据。（错误，Date数据类型能够精确的秒，如dd-mon-yyyy HH24:MI:SS)
B: CUST_CREDIT_VALUE字段能存储正整数和负整数。（正确）
C: TRANS_VALIDITY字段能存储包括天、小时、分钟、秒的时间段（正确）
D: CUST_STATUS 字段最大能存储4000个字符。（错误，没有指定最大值。会报错）
这道题能够參见上道题：http://blog.csdn.net/wjx515628/article/details/35623657
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字段仅仅能存储如dd-mon-yyyy格式的数据。（错误，Date数据类型能够精确的秒，如dd-mon-yyyy HH24:MI:SS)
B: CUST_CREDIT_VALUE字段能存储正整数和负整数。（正确）
C: TRANS_VALIDITY字段能存储包括天、小时、分钟、秒的时间段（正确）
D: CUST_STATUS 字段最大能存储4000个字符。（错误，没有指定最大值。会报错）
这道题能够參见上道题：http://blog.csdn.net/wjx515628/article/details/35623657