AFTER trigger execution in SQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an AFTER trigger in SQL?

An AFTER trigger is a database trigger that runs automatically after a specified data modification event like INSERT, UPDATE, or DELETE has completed successfully.

beginner

When does an AFTER trigger execute in relation to the triggering SQL statement?

An AFTER trigger executes only after the triggering SQL statement has completed successfully.

intermediate

Can an AFTER trigger modify the data that caused it to fire?

No, AFTER triggers cannot modify the data that caused them to fire because the original statement has already completed. They can only perform additional actions like logging or cascading changes.

beginner

Give an example use case for an AFTER trigger.

An AFTER trigger can be used to log changes to a table by inserting a record into an audit table after a row is inserted or updated.

intermediate

What happens if an AFTER trigger fails during execution?

If an AFTER trigger fails, the entire transaction that fired the trigger is rolled back, undoing the original data modification.

When does an AFTER trigger run in SQL?

A Only when a SELECT statement runs

B Before the data modification statement executes

C At the same time as the data modification statement

D After the data modification statement completes successfully

AFTER triggers run only after the triggering data modification statement (INSERT, UPDATE, DELETE) completes successfully.

Which of the following can an AFTER trigger NOT do?

A Log changes to another table

B Send notifications

C Modify the data that caused the trigger to fire

D Enforce complex business rules after data change

AFTER triggers cannot modify the data that caused them to fire because the original statement has already completed.

If an AFTER trigger fails, what happens to the original data change?

A The data change is rolled back

B Only the trigger fails, data change is ignored

C The data change remains committed

D The database shuts down

If an AFTER trigger fails, the entire transaction including the original data change is rolled back.

Which SQL events can an AFTER trigger be defined on?

A INSERT, UPDATE, DELETE

B SELECT only

C CREATE and DROP

D ALTER only

AFTER triggers are commonly defined on data modification events: INSERT, UPDATE, and DELETE.

What is a common use of AFTER triggers?

A To validate data before insertion

B To log audit information after data changes

C To speed up SELECT queries

D To create new tables automatically

AFTER triggers are often used to log audit information or perform actions after data changes.

Explain what an AFTER trigger is and when it executes in a database.

Think about what happens after you save changes in a spreadsheet.

Describe a practical scenario where you would use an AFTER trigger and why.

Consider tracking changes after they happen.