Q26: Which query ensures each project appears only once, even if multiple people work on it?

Question

BlackTom AI · Accepted Answer

RETURN DISTINCT is the core mechanism that removes duplicate rows in Cypher, so returning DISTINCT p will collapse multiple matches of the same project node into a single result.

Relevant concepts:
- MATCH (:Person)-[:WORKS_ON]->(p:Project) finds every pattern where a Person works on a Project; if multiple people work on the same project, that project node p will be matched multiple times.
- RETURN p without DISTINCT yields one row per match, so duplicates can appear.
- RETURN DISTINCT p deduplicates identical p values so each project node appears only once.
- MATCH (p:Project) RETURN p directly enumerates all Project nodes once (Cypher returns each matched node a single time when matching by node variable), so it also yields each project just once.

Step-by-step reasoning with a simple example:
1. Suppose Project P1 has Person A and Person B linked: two pattern matches for p = P1.
2. Query A: MATCH (:Person)-[:WORKS_ON]->(p:Project) RETURN p
   - Matches produce two rows: p = P1, p = P1 → duplicates remain.
3. Query B: MATCH (:Person)-[:WORKS_ON]->(p:Project) RETURN DISTINCT p
   - Matches produce two candidate rows but DISTINCT collapses them to one row: p = P1.
4. Query C: MATCH (p:Project) RETURN p
   - Directly matches each project node once, so p = P1 appears a single time.

Why the correct answer is correct:
- Both B and C ensure each project appears only once. B deduplicates projects even when matched multiple times via relationships. C lists projects directly and returns each node once.

Why other options are incorrect:
- Option A returns duplicates when multiple people work on the same project.
- Option E (None of the above) is false because B and C do meet the requirement.

Final confirmation: The correct answer is "Both B and C," matching the provided answer.

Q26: Which query ensures each project appears only once, even if multiple people work on it?Single choice

Similar Questions

Q25: Which query returns people who authored work from projects funded by Innovation?

Q 22: Which query returns works authored by someone who is also a Researcher?

Q 21: Which query returns total hours worked on each project?

Q 19: Which query returns the department that funds the project Alice works on?

Q 12: Which query returns only people who are BOTH Engineer AND Researcher?

Which of the following queries could return the same person–movie pair more than once, even if the dataset guarantees that there is at most one PRODUCED relationship and at most one REVIEWED relationship between any person and movie

Which queries find people who both acted in and directed the same movie in neo4j's sample Movie Graph? Select all that apply.

According to Xenophanes, what should be avoided at a symposium?

More Practical Tools for Students Powered by AI Study Helper

Homework AI Solver

Stylized AI Paper Writer

Plagiarism Checker Assistant

Citation AI Academic Writing Tool

In-Class Translation Assistant

AI Note Generator

AI Quiz Answers

Past Exam Questions from University Test Bank

Smart Practice Assistant

Adaptive Practice

Making Your Study Simpler