Câu 13: DS0-001: CompTIA DataSys+

A business analyst is using a client table and an invoice table to create a database view that shows clients who have not made purchases yet. Which of the following joins is most appropriate for the analyst to use to create this database view?

1. A. INNER JOIN ON Client.Key = Invoice.Key
2. B. RIGHT JOIN ON Client.Key = Invoice.Key WHERE BY Client.Key IS NULL
3. C. LEFT JOIN ON Client.Key = Invoice.Key
4. D. LEFT JOIN ON Client.Key = Invoice.Key WHERE BY Invoice.Key IS NULL — đáp án hiện tại