SQL Database Data Change Operations (Insert, Update, Delete) Quiz

When adding a new row, which keyword begins the operation?

If a table has a column with a default value, what happens when you omit it in an INSERT?

If you want only certain columns to receive values, you typically:

Imagine collecting registrations for an event. Each time a new attendee signs up, which operation records their data as a new row?

Why is the order of values in an INSERT important when no column list is provided?

If you want to add several rows at once, which INSERT approach helps reduce repetitive commands?

You are adding product records for a catalog. Which method avoids inserting unnecessary NULLs?

INSERTing a row without specifying a NOT NULL column results in:

What happens when you INSERT a value into a unique key column that already exists?

Inserting rows with mismatched column/value counts typically:

What does this command do?

INSERT INTO users (name, age) VALUES ('Mila', 27);

Interpret this INSERT:

INSERT INTO books VALUES (101, 'Atlas Guide', 19.99);

This command inserts two rows at once:

INSERT INTO tags (label) VALUES ('blue'), ('green');

What is inserted?

INSERT INTO inventory (item, quantity) VALUES ('Brush', 0);

What does this produce?

INSERT INTO logs (event, created_at) VALUES ('login', NOW());

What will this do?

INSERT INTO scores (player, score) VALUES ('Tom', score + 10);

Evaluate this:

INSERT INTO guests (name) SELECT user_name FROM applicants;

Which value is inserted?

INSERT INTO payments (amount) VALUES (NULL);

What happens here?

INSERT INTO cities (name, population) VALUES ('Paris');

Interpret this multi-value pattern:

INSERT INTO metrics (type, value) VALUES ('views', 100), ('clicks', 12);

Predict the result:

INSERT INTO actors (id, name) VALUES (5, 'Nia');

Look at this INSERT:

INSERT INTO comments (text, created_at) VALUES ('Hello', DEFAULT);

Interpret the source of inserted rows:

INSERT INTO archive_logs SELECT * FROM logs WHERE severity = 'high';

Evaluate this INSERT structure:

INSERT INTO tmp_sessions (session_id) VALUES ('xyz'), ('abc'), ('lmn');

What type of insertion is shown?

INSERT INTO audit (event) SELECT action FROM activity;

Which operation changes values in existing rows?

Why is the WHERE clause critical in UPDATE?

Imagine adjusting prices during a sale. Updating all products to 10% off requires:

When updating multiple columns, SET:

If your UPDATE affects zero rows, it usually means:

Why might an UPDATE adjust a timestamp using NOW()?

Updating rows without a WHERE clause is usually considered:

Imagine marking a user account as inactive. Which operation suits this?

Which statement best describes UPDATE?

Updating with expressions like SET count = count + 1 is commonly used to:

What changes here?

UPDATE users SET active = 0 WHERE last_login < '2023-01-01';

Interpret this:

UPDATE products SET price = price * 1.05;

What happens?

UPDATE employees SET dept = 'Sales' WHERE id = 4;

What is modified?

UPDATE tasks SET completed_at = NOW() WHERE completed = 1;

Interpret the result:

UPDATE accounts SET balance = balance - 50 WHERE id = 10;

What does this change?

UPDATE messages SET seen = 1 WHERE user_id = 8;

What is updated?

UPDATE books SET stock = 0 WHERE stock < 0;

Predict the update:

UPDATE tickets SET priority = 'high' WHERE urgent = 1;

What is changed?

UPDATE settings SET value = 'on' WHERE key = 'notifications';

Interpret this change:

UPDATE students SET grade = grade + 1 WHERE grade < 90;

What happens?

UPDATE cards SET expired = 1 WHERE expires_at < NOW();

Analyze this:

UPDATE reports SET reviewed_by = 'Admin' WHERE reviewed_by IS NULL;

What does this do?

UPDATE drivers SET city = 'LA' WHERE city = 'Los Angeles';

Interpret this:

UPDATE activity SET count = 0 WHERE count IS NULL;

What is updated?

UPDATE articles SET views = views + 10;

Which command removes rows?

Why is WHERE essential in DELETE?

Imagine cleaning old system logs. Removing only logs older than 30 days requires:

What happens if a DELETE matches no rows?

Deleting without WHERE generally:

DELETE differs from UPDATE because DELETE:

Imagine a user requests account removal. Which operation removes that user's record completely?

DELETE operations require caution because:

Using DELETE to clean temporary data is common because:

DELETE without filtering is similar to:

What rows are removed?

DELETE FROM logs WHERE level = 'debug';

Interpret this:

DELETE FROM customers WHERE inactive = 1;

What is removed?

DELETE FROM posts WHERE created_at < '2022-01-01';

What happens?

DELETE FROM events WHERE id = 7;

Which rows disappear?

DELETE FROM reviews WHERE rating = 1 OR flagged = 1;

Interpret this removal:

DELETE FROM queue WHERE attempts > 3;

What does this delete?

DELETE FROM orders WHERE status = 'cancelled';

Evaluate this deletion:

DELETE FROM students WHERE grade < 60;

Predict the effect:

DELETE FROM store_items WHERE discontinued = 1;

Which rows get deleted?

DELETE FROM sessions WHERE active = 0 AND expires_at < NOW();

What is removed?

DELETE FROM accounts WHERE last_active IS NULL;

Interpret this deletion:

DELETE FROM payments WHERE amount = 0;

What happens?

DELETE FROM audit WHERE created_at > NOW();

Which rows disappear?

DELETE FROM leads WHERE source LIKE '%test%';

What gets deleted here?

DELETE FROM accounts WHERE status IN ('blocked','fraud');