Question

What does inner_join() do with rows that cannot be matched?

A) Retains unmatched rows with NA values in the result
B) Excludes unmatched rows from the result
C) Substitutes missing values for unmatched rows
D) Creates a separate dataset for unmatched rows

Answer 1

The function inner_join() excludes unmatched rows from the result, including only those rows that have matching values in both tables being joined.

Step-by-step explanation:

The function inner_join() in data manipulation contexts (such as SQL databases or data frame operations in programming languages like R) is used to combine rows from two or more tables based on a related column between them. The inner_join() operation includes in the result only those rows that have matching values in both tables. Therefore, the answer to what inner_join() does with rows that cannot be matched is B) Excludes unmatched rows from the result. If there are rows in either table that do not have a corresponding match in the other, those rows will be excluded from the final result set produced by the inner join operation.