Question

The SELECT command when combined with DISTINCT clause is used to:

• A. returns records without repetition
• B. returns records with repetition
• C. returns all records with conditions
• D. returns all records without checking

Hint:

Always use DISTINCT when you want to remove duplicates and retrieve only unique results in SQL queries.

Answer 1

The Correct Option is A

Step 1: Understanding DISTINCT.
The DISTINCT keyword in SQL ensures that duplicate records are eliminated from the result set. Only unique values are returned.
Step 2: Example.
Suppose a column has values: (10, 20, 10, 30).
\begin{verbatim} SELECT DISTINCT column_name FROM table; \end{verbatim} This will return: (10, 20, 30).
Step 3: Eliminate wrong options.
- Option 2: Incorrect, DISTINCT never returns duplicates.
- Option 3: Incorrect, conditions are applied using WHERE clause.
- Option 4: Incorrect, DISTINCT does check and removes duplicates.

Final Answer: \[ \boxed{\text{Returns records without repetition}} \]