Which clause eliminates duplicate values from the result set?

Which clause eliminates duplicate values from the result set?

• A. SELECT DISTINCT
• B. SELECT ALL
• C. SELECT UNIQUE
• D. SELECT TOP

Answer: (A)

In SQL, to remove duplicate rows from the result set you use the DISTINCT clause. It checks the values of the columns you select and keeps only one row for each unique combination of those values, so you don’t get repeated rows in the output. The operation happens after filtering and joining, but before the final result is returned, ensuring every row is distinct with respect to the selected columns. All is the default behavior and does not filter duplicates, so you’d see every matching row unless you explicitly request deduplication. UNIQUE is a dialect-specific synonym in some systems but isn’t guaranteed everywhere, so DISTINCT is the most portable choice. TOP, on the other hand, restricts how many rows are returned and does not remove duplicates by itself.

In SQL, to remove duplicate rows from the result set you use the DISTINCT clause. It checks the values of the columns you select and keeps only one row for each unique combination of those values, so you don’t get repeated rows in the output. The operation happens after filtering and joining, but before the final result is returned, ensuring every row is distinct with respect to the selected columns.

All is the default behavior and does not filter duplicates, so you’d see every matching row unless you explicitly request deduplication. UNIQUE is a dialect-specific synonym in some systems but isn’t guaranteed everywhere, so DISTINCT is the most portable choice. TOP, on the other hand, restricts how many rows are returned and does not remove duplicates by itself.