73. Which tasks can be performed using SQL functions that are built into Oracle database ? (Choose
three .)
A. finding the remainder of a division
B. adding a number to a date for a resultant date value
C. comparing two expressions to check whether they are equal
D. checking whether a specified character exists in a given string
E. removing trailing, leading, and embedded characters from a character string
Answer: ACD
答案解析：
A. 取余，如MOD()
B. 给日期添加一个数字合成一个日期值,个人觉得可以使用ADD_MONTHS()，含义上也是一个日期加上一个数字等于另外一个日期。
C. 比较两个表达式查看是否相等,例如NULLIF
D. 检查指定的字符串是否存在另一个字符串中,例如，INSTR()
E. 从一个字符串中移除尾部，前部，内含的字符,trim()只能去除前后的字符