OCP 11g考试题库详解：1Z0-051-098题

OCP 11g考试题库详解：1Z0-051-098题，完整题库请点击这里联系老师咨询了解

98. Which statement is true regarding the COALESCE function?

A. It can have a maximum of five expressions in a list. 

B. It returns the highest NOT NULL value in the list for all rows.

C. It requires that all expressions in the list must be of the same data type.

D. It requires that at least one of the expressions in the list must have a NOT NULL value.

Answer: C

A 最多只能有5个表达式，错，无限个

B 返回最高的非空值，错，返回第一个非空值

C 所有都要相同的类型

D 至少有一个不是空值，错，可以都是空值，则返回空值