CompTIA Data+ DA0-002 (V2) Practice Question

The correct answer is GROUP BY. The GROUP BY clause is used in SQL with aggregate functions (like SUM(), COUNT(), AVG()) to collect data from multiple records and group the results by one or more columns. In this scenario, it would be used to group all transactions by 'CustomerID' so the SUM() of 'SaleAmount' can be calculated for each customer. The ORDER BY clause is used to sort the result set, not to aggregate it. A FILTER operation (typically using a WHERE clause) would select specific rows before aggregation but would not perform the aggregation itself. A JOIN clause is used to combine rows from two or more tables, which is not the primary requirement described in the scenario.