Computer Science for IGCSE & O level - Databases (Section 6 - No. 9)
What is the purpose of the `GROUP BY` clause in an SQL query?
To sort the result set.
To filter the results based on conditions.
To combine rows that have the same values in one or more columns into a summary row.
To specify the table(s) from which to retrieve data.
Giải thích
The `GROUP BY` clause aggregates data by grouping rows with the same values in one or more columns.