フリー問題

問題文

A trainee is told that some functions are single-row functions and others are group functions. Which statement separates the two correctly?

選択肢

1. A single-row function returns one result for each row it is applied to while a group function returns one result for each table in the query.
2. A single-row function returns one result for a set of rows while a group function returns one result for each row it applies to.
3. A single-row function returns one result for each row it is applied to while a group function returns one result for the set of the rows.
4. A single-row function returns one result for each row it is applied to while a group function returns one result for each column in the select list.