User feedback collection in No-Code - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ query_result

intermediate

Retrieve all feedback entries submitted in the last 7 days

Given a feedback database table with columns id, user_id, comment, and submitted_at, which query returns all feedback submitted in the last 7 days?

A SELECT * FROM feedback WHERE submitted_at < CURRENT_DATE + INTERVAL '7 days';

B SELECT * FROM feedback WHERE submitted_at >= CURRENT_DATE - INTERVAL '7 days';

C SELECT * FROM feedback WHERE submitted_at <= CURRENT_DATE - INTERVAL '7 days';

D SELECT * FROM feedback WHERE submitted_at > CURRENT_DATE + INTERVAL '7 days';

💡 Hint

Think about how to select dates from the recent past, not the future.

Option B correctly selects feedback where the submission date is within the last 7 days by subtracting 7 days from the current date. Other options either select future dates or dates older than 7 days.

🧠 Conceptual

intermediate

Understanding the purpose of a feedback table's user_id column

Why is the user_id column important in a user feedback collection database?

A It records the date and time when feedback was submitted.

B It stores the text of the feedback comment.

C It links feedback to the user who submitted it, enabling personalized follow-up.

D It counts the total number of feedback entries.

💡 Hint

Think about how to connect feedback to the person who gave it.

The user_id column connects each feedback entry to the specific user who submitted it, which helps in tracking and responding to feedback personally.

📋 Factual

advanced

Identify the syntax error in this feedback insertion query

Which option contains a syntax error when inserting a new feedback entry with user_id 5 and comment 'Great app!'?

A NSERT INTO feedback (user_id, comment) VALUES (5, 'Great app!');

B INSERT INTO feedback (user_id, comment) VALUES (5, 'Great app!');

C ;)'!ppa taerG' ,5( SEULAV )tnemmoc ,di_resu( kcabdeef OTNI TRESNI

D INSERT INTO feedback user_id, comment VALUES (5, 'Great app!');

💡 Hint

Check the syntax for specifying columns in an INSERT statement.

Option D is missing parentheses around the column names, which is required syntax in SQL INSERT statements.

❓ optimization

advanced

Optimize query to count feedback per user efficiently

Which query efficiently counts the number of feedback entries per user?

A SELECT user_id, COUNT(*) FROM feedback GROUP BY user_id;

B SELECT user_id, COUNT(*) FROM feedback;

C SELECT COUNT(user_id) FROM feedback GROUP BY user_id;

D SELECT user_id, COUNT(user_id) FROM feedback WHERE user_id IS NOT NULL;

💡 Hint

Think about grouping results by user to get counts per user.

Option A correctly groups feedback by user_id and counts entries per user. Option A lacks GROUP BY, C returns counts but no user_id, and D filters but misses grouping.

🔍 Analysis

expert

Find the cause of missing feedback entries in query result

A query to select feedback with comments containing 'bug' returns no rows, but there are entries with 'Bug' and 'BUG'. What is the cause?

No-Code

SELECT * FROM feedback WHERE comment LIKE '%bug%';

A The query is case-sensitive and misses 'Bug' and 'BUG' due to letter case differences.

B The query syntax is incorrect and causes no results.

C The feedback table is empty.

D The LIKE operator does not support wildcards.

💡 Hint

Consider how SQL handles text matching and case sensitivity.

The LIKE operator is case-sensitive in many databases, so it misses entries with different letter cases. Using case-insensitive search or functions can fix this.