COMMIT and ROLLBACK behavior in SQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the COMMIT command do in SQL?

COMMIT saves all changes made in the current transaction permanently to the database.

beginner

What happens when you use ROLLBACK in SQL?

ROLLBACK undoes all changes made in the current transaction, restoring the database to its previous state.

beginner

When should you use COMMIT in a transaction?

Use COMMIT after you have completed all your changes and want to save them permanently.

intermediate

Can you undo a COMMIT with ROLLBACK?

No, once you COMMIT, changes are permanent and cannot be undone by ROLLBACK.

beginner

What is a transaction in SQL?

A transaction is a group of one or more SQL statements executed as a single unit, which can be committed or rolled back together.

What does the ROLLBACK command do?

A Undoes changes in the current transaction

B Saves changes permanently

C Starts a new transaction

D Deletes the database

ROLLBACK undoes all changes made in the current transaction.

When are changes saved permanently in a database?

A After ROLLBACK

B When the database is restarted

C Before starting a transaction

D After COMMIT

COMMIT saves changes permanently.

Can you undo a COMMIT with ROLLBACK?

A Yes, always

B Only if the database supports it

C No, COMMIT is permanent

D Only within 5 minutes

Once committed, changes cannot be undone by ROLLBACK.

What is a transaction?

A A group of SQL statements executed as one unit

B A backup of the database

C A single SQL statement

D A database user

A transaction groups SQL statements to be committed or rolled back together.

Which command permanently saves changes made in a transaction?

A SAVEPOINT

B COMMIT

C ROLLBACK

D BEGIN

COMMIT saves all changes permanently.

Explain the difference between COMMIT and ROLLBACK in SQL.

Think about saving vs undoing changes.

Describe what a transaction is and how COMMIT and ROLLBACK affect it.

Consider a transaction like a batch of changes.