Question

Match List-I with List-II: 

List-I	List-II
(A) Retrieve all rows with duplicates removed	(I) GROUP BY
(B) Filter rows based on condition	(II) ORDER BY
(C) Aggregate data into groups	(III) DISTINCT
(D) Sort rows in ascending or descending order	(IV) WHERE

Choose the correct answer from the options given below: 

• (A) - (IV), (B) - (III), (C) - (I), (D) - (II)
• (A) - (I), (B) - (II), (C) - (III), (D) - (IV)
• (A) - (III), (B) - (IV), (C) - (I), (D) - (II)
• (A) - (III), (B) - (IV), (C) - (II), (D) - (I)

Hint:

Quick SQL Clause Recall:
- DISTINCT = Remove duplicates.
- WHERE = Filter tuples.
- GROUP BY = Form summary groups.
- ORDER BY = Sort rows.

Answer 1

The Correct Option is C

Concept:
SQL keywords and clauses provide specialized operations to query, filter, structure, and manipulate relational data sets.

Step 1: Functional Analysis of Each Clause:
1. DISTINCT (III): The DISTINCT keyword is placed directly after SELECT to eliminate duplicate values from the output, returning only unique records. Thus, (A) matches with (III).
2. WHERE (IV): The WHERE clause filters tuples from a table based on specified conditional criteria before any grouping occurs. Thus, (B) matches with (IV).
3. GROUP BY (I): The GROUP BY clause summarizes rows that have identical values in specified columns into aggregate summary rows. Thus, (C) matches with (I).
4. ORDER BY (II): The ORDER BY clause sorts the final result set in either ascending (ASC) or descending (DESC) order. Thus, (D) matches with (II).

Step 2: Alignment of Pairs:
The resulting configuration is:
(A) $\rightarrow$ (III)
(B) $\rightarrow$ (IV)
(C) $\rightarrow$ (I)
(D) $\rightarrow$ (II)
Final Answer:
This matches correctly with option (C).