What is the role of a trigger in a database and why is it used?

A trigger in a database is a special mechanism that automatically executes a predefined set of actions (such as SQL queries or procedures) when certain events occur, such as inserting, updating, or deleting data.

The main purposes of using triggers are:

• Automating data integrity checks.
• Logging changes in tables.
• Implementing complex business logic at the database level.
• Synchronizing data between tables.

For example, when a new record is added to the orders table, a trigger can automatically update the available stock quantity.