Data Engineering Associate with Databricks Practice Exam

Which SQL command would be used to check for record matches in a merge operation?

1. WHEN MATCHED

2. IF EXISTS

3. IF MATCHED

4. ON MATCH FOUND

The correct answer is: WHEN MATCHED

In a merge operation, the SQL command used to check for record matches is "WHEN MATCHED." This command is part of the MERGE statement in SQL, which allows for conditional updates, inserts, and deletions based on whether a specified condition is met for the records being merged. The "WHEN MATCHED" clause specifies what action should be taken when a record from the target table matches a record from the source table based on the defined criteria. This is essential for streamlining and optimizing data updates or changes, ensuring that the right records are handled appropriately. The other options do not accurately represent the syntax used in a merge operation. Utilizing "IF EXISTS," "IF MATCHED," or "ON MATCH FOUND" does not align with the standard SQL syntax for merging records or checking for matches. Thus, "WHEN MATCHED" is the correct and necessary command to facilitate the logic of a merge operation effectively.