【ocp-12c】最新Oracle OCP-071考试题库(47题)
47、(10-6)choose two You need to calculate the number of days from 1st January 2007 till date. Dates are stored in the default format of dd-mon-rr. Which two SQL statements would give the required output? A) SELECT TO_DATE (SYSDATE,‘DD/MONTH/YYYY‘) - ‘01/JANUARY/2007‘ FROM DUAL; B) SELECT SYSDATE - TO_DATE (‘01/JANUARY/2007‘) FROM DUAL; C) SELECT SYSDATE -‘01-JAN-2007‘ FROM DUAL; D) SELECT SYSDATE - TO_DATE (‘01-JANUARY-2007‘) FROM DUAL; E) SELECT TO_CHAR (SYSDATE,‘DD-MOM-YYYY‘) - ‘01-JAN-2007‘ FROM DUAL; Answer:BD (解析:对数据进行混合运算时必须要用转换函数转换为日期格式,因为它不会隐式转换,但是我们在insert 数据时,会实现隐式转换。 SQL> SELECT SYSDATE - TO_DATE (‘01-1 月-2007‘) FROM DUAL; 或者: SQL> SELECT SYSDATE - TO_DATE (‘01/1 月/2007‘) FROM DUAL; ? ) (编辑:李大同) 【声明】本站内容均来自网络,其相关言论仅代表作者个人观点,不代表本站立场。若无意侵犯到您的权利,请及时与联系站长删除相关内容! |