ORACLE11G OCP-051 第86题

86. Examine the structure and data of the CUST_TRANS table:

下面是CUST_TRANS的表结构和表中的数据

CUST_TRANS

Name                 Null                  Type

CUSTNO           NOT NULL      CHAR(2)

TRANSDATE                               DATE

TRANSAMT                                 NUMBER(6,2)

CUSTNO          TRANSDATE            TRANSAMT

11                    01-JAN-07                  1000
22                    01-FEB-07                  2000

33                    01-MAR-07                 3000

Dates are stored in the default date format dd-mon-rr in the CUST_TRANS table. Which SQL statements would execute successfully? (Choose three .)

表中的日期使用了默认的日期格式 dd-mon-rr ，下面那些个语句是可以执行成功的。（选择3个）

A. SELECT transdate + '10' FROM cust_trans;    

B. SELECT * FROM cust_trans WHERE transdate = '01-01-07';

C. SELECT transamt FROM cust_trans WHERE custno > '11';

D. SELECT * FROM cust_trans WHERE transdate='01-JANUARY-07';

E. SELECT custno + 'A' FROM cust_trans WHERE transamt > 2000;

答案：ACD

B：日期格式不一致，不能隐式转换，需要使用to_date

E：A是字符，发生隐式转换时不能转换为数字，会报错