OCP-1Z0-051-Question Analysis-4th question

4. Which two statements are true regarding single row functions? (Choose two .)

A. They a ccept only a single argument.

B. They can be nested only to two levels.

C. Arguments can only be column values or constants.

D. They a lways return a single result row for every row of a queried table.

E. They can return a data type value different from the one that is referenced.

Answer: DE

Question Analysis:

A: A single-row function can only accept one parameter (for example, to_date ('20140901', 'yy-mm-dd)

B: single-row functions can only be nested at two levels (incorrect, can be nested at multiple levels)

C: single-line function parameters can only be fields or constants (errors, parameters can also be variables or expressions)

D: only one result can be returned for each row (correct, this is a feature of a single row function)

E: the data type returned by a single-row function can be different from the previous reference value (correct, for example, data type conversion function, to_char, to_date, etc)