Most Helpful Reviews
Find top 5 reviews by helpful_votes.
The challenge runs on the SQLabHub practice database (SQLite) and uses the reviews table. You can solve it in the browser, with nothing to install.
The task
Find top 5 reviews by helpful_votes.
A correct answer returns 5 rows with 7 columns: id, product_id, user_id, rating, comment, reviewed_at, helpful_votes.
Tables used in this challenge
reviews 180 rows
id INTEGER (PK) · product_id INTEGER · user_id INTEGER · rating INTEGER · comment TEXT · reviewed_at TEXT · helpful_votes INTEGER
| id | product_id | user_id | rating | comment | reviewed_at | helpful_votes |
|---|---|---|---|---|---|---|
The first rows of each table are shown. See how all the tables relate on the database schema page.
Expected output
| id | product_id | user_id | rating | comment | reviewed_at | helpful_votes |
|---|---|---|---|---|---|---|
The complete result: 5 rows. This is the output of the model solution on the practice database.
What you practise
- Returning every column of a table with SELECT *
- Sorting the result with ORDER BY
- Returning only the first rows with LIMIT
Hint and approach
Try the challenge first. Open these only when you need them.
Show the hint
ORDER BY votes DESC LIMIT
Show the step-by-step approach
How the model solution is built, in the order the database evaluates it:
- Read from the
reviewstable. - Return every column with
SELECT *. - Sort the result by
helpful_votesdescending. - Keep only the first 5 rows with
LIMIT.
Model solution
Checking your session…
What to watch for
- LIMIT. LIMIT without ORDER BY returns an arbitrary set of rows. LIMIT is also dialect-specific: SQL Server uses TOP and Oracle uses FETCH FIRST.
- ORDER BY. Without ORDER BY the row order is not guaranteed, even if it looks stable. Rows that tie on the sort columns can come back in any order.
- SELECT *. SELECT * is fine for exploring, but its output changes whenever a column is added to the table. Queries that feed a report should name their columns.
Related SQL challenges
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- Find the Top 5 Customers by Total SpendHarderMedium
- Select All Columns from a Table with LIMITSimilar levelEasy
- Sort Employees by Salary, Highest FirstSimilar levelEasy
Keep learning
- Lesson: LIMIT / TOP / FETCH
- Lesson: ORDER BY
- Lesson: The BIG 6 SQL Clauses
- All SQL practice challenges, by difficulty and topic
- SQL interview questions with answers
- SQL Playground: run any query on the same database