Feedback collection and annotation in LangChain - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ query_result

intermediate

Retrieve all feedback entries with annotations

Given a database table feedback with columns id, comment, and annotation, which SQL query returns all feedback comments along with their annotations?

A SELECT comment, annotation FROM feedback;

B SELECT id, comment FROM feedback WHERE annotation IS NOT NULL;

C SELECT * FROM feedback WHERE annotation IS NULL;

D SELECT annotation FROM feedback;

💡 Hint

Think about selecting both the comment and its annotation for all entries.

Option A selects both comment and annotation columns from all rows, which matches the requirement.

Option A filters only feedback without annotations.

Option A excludes annotations from the result.

Option A selects only annotations without comments.

🧠 Conceptual

intermediate

Understanding annotation storage in feedback systems

Why is it important to store annotations separately from the original feedback comments in a database?

A To allow multiple annotations per feedback without changing the original comment.

B To prevent users from submitting feedback.

C To make feedback comments unreadable without annotations.

D To reduce the size of the database by splitting data.

💡 Hint

Think about how annotations might be added or changed over time.

Storing annotations separately allows adding multiple notes or updates without altering the original feedback, preserving its integrity.

Options A, B, and C do not reflect practical reasons for separate storage.

📝 Syntax

advanced

Identify the correct SQL syntax to update a feedback annotation

Which SQL statement correctly updates the annotation of a feedback entry with id = 5 to 'Reviewed and approved'?

A CHANGE feedback annotation TO 'Reviewed and approved' WHERE id = 5;

B MODIFY feedback SET annotation = 'Reviewed and approved' WHERE id = 5;

C UPDATE feedback SET annotation = 'Reviewed and approved' WHERE id = 5;

D UPDATE feedback WHERE id = 5 SET annotation = 'Reviewed and approved';

💡 Hint

Recall the standard SQL syntax for updating records.

Option C uses the correct UPDATE ... SET ... WHERE ... syntax.

Options A, B, and D use invalid or incorrect SQL syntax.

❓ optimization

advanced

Optimizing feedback annotation queries

You have a large feedback table with millions of rows. Which approach will optimize queries filtering feedback by annotation status?

A Store annotations in a separate text file outside the database.

B Create an index on the <code>annotation</code> column.

C Remove the <code>annotation</code> column to speed up queries.

D Use SELECT * without WHERE clause to avoid filtering overhead.

💡 Hint

Think about how databases speed up searches on specific columns.

Creating an index on the annotation column helps the database quickly find rows matching annotation filters.

Options B, C, and D either reduce functionality or increase workload.

🔧 Debug

expert

Debugging a feedback annotation insertion error

Given the table feedback with columns id (auto-increment), comment (text), and annotation (text), which INSERT statement will cause an error?

Assume id is auto-generated and should not be manually inserted.

A INSERT INTO feedback (comment, annotation) VALUES ('Great app', 'Positive');

B INSERT INTO feedback (id, comment, annotation) VALUES (NULL, 'Needs improvement', 'Negative');

C INSERT INTO feedback (comment) VALUES ('No annotation yet');

D INSERT INTO feedback (id, comment) VALUES (10, 'Manual id insertion');

💡 Hint

Consider how auto-increment columns behave when manually inserting values.

Option D tries to manually insert a value into the auto-increment id column, which can cause a conflict or error depending on database settings.

Option D inserts NULL for id, which is allowed to trigger auto-increment.

Options B, C, and D are valid inserts.