In SQL and relational databases, what do we call a stored program attached to a table or view that automatically fires in response to DML events (INSERT, UPDATE, DELETE)?
-
APseudofile
-
BEmbedded SELECT statement
-
CTrigger
-
DAuto-procedure
-
ERowset macro
Answer
Correct Answer: Trigger
Explanation
Introduction / Context:Automation in databases often relies on server-side programs that react to data changes. These programs help enforce integrity, transform data, or audit changes close to the data.
Given Data / Assumptions:
- The mechanism is attached to a table or view.
- It fires automatically on INSERT, UPDATE, or DELETE events.
- It runs inside the same transaction as the triggering statement.
Concept / Approach:A trigger is a stored routine associated with a table or view that executes in response to DML events. Triggers can be BEFORE or AFTER (depending on RDBMS), row-level or statement-level, and are used for auditing, denormalized updates, validation, and enforcing complex constraints not expressible with CHECK or foreign keys.
Step-by-Step Solution:
Identify the behavior: automatic execution on DML.Map to database feature → trigger.Confirm scope: bound to a table or a view, not free-standing.Verification / Alternative check:RDBMS documentation consistently defines triggers as the event-driven database programs attached to tables/views.
Why Other Options Are Wrong:Pseudofile / Rowset macro / Auto-procedure: Not standard SQL terms. Embedded SELECT statement: A query inside another, not an event-driven routine.
Common Pitfalls:Overusing triggers for business logic that belongs in the application; triggers should be reserved for data-integrity concerns or unavoidable side effects.
Final Answer:Trigger