Learn to use SQL Views, Stored Procedures, and Triggers. Build real-world skills with hands-on practice, and run SQL queries directly in your browser.

Become a Database Professional with SQL

This module guides you through key concepts like Views, Stored Procedures, and Triggers. You'll learn to create, update, and manage views. Next, you'll explore stored procedures—covering variables, parameters, loops, conditionals, cursors, and error handling with SIGNAL and RESIGNAL. You'll also explore stored functions. Finally, you’ll master triggers for INSERT, UPDATE, and DELETE operations, including handling multiple triggers. You'll practice SQL directly in your browser and gain real-world skills through hands-on tasks.

SQL Views, Stored Procedures and Triggers

# What are Triggers?
Triggers are MySQL programs that are executed automatically in response to an event. They are associated with tables. More specifically, a trigger is invoked in response to events that change the contents of a table like the __INSERT__, __UPDATE__, and __DELETE__ statements. Triggers can be invoked before or after these events take place.


The SQL standard specifies two types of triggers; row-level triggers and statement-level triggers. The former are invoked when a row is inserted, updated or deleted. Say, if a query updates 25 rows, then a row-level trigger will be invoked as many times. The latter type of triggers are invoked once per statement even if the statement targets 25 rows. MySQL only provides support for row-level triggers.

Triggers offer a number of advantages. They prevent invalid DML statements from executing and are used to handle errors from the database layer by ensuring data integrity. Triggers provide an alternative to __scheduled events__. Scheduled events in MySQL are invoked at a specified time whereas triggers are invoked whenever a DML statement is executed. Triggers are also useful for auditing purposes and keeping a log of changes made to a table.


This lesson provides an introduction to triggers and discusses the benefits and trade-offs of using them.