Advantage of Triggers

The benefits of using triggers in SQL Server include the following:

1. Database object rules are established by triggers, which cause changes to be undone if they are not met. 
2. The trigger will examine the data and, if necessary, make changes.
3. We can enforce data integrity thanks to triggers.
4. Data is validated using triggers before being inserted or updated.
5. Triggers assist us in maintaining a records log.
6. Due to the fact that they do not need to be compiled each time they are run, triggers improve the performance of SQL queries.
7. The client-side code is reduced by triggers, saving time and labor.
8. Trigger maintenance is simple.

A trigger is a stored procedure in a database that automatically invokes whenever a special event in the database occurs. For example, a trigger can be invoked when a row is inserted into a specified table or when specific table columns are updated. In simple words, a trigger is a collection of SQL statements with particular names that are stored in system memory. It belongs to a specific class of stored procedures that are automatically invoked in response to database server events. Every trigger has a table attached to it.

Because a trigger cannot be called directly, unlike a stored procedure, it is referred to as a special procedure. A trigger is automatically called whenever a data modification event against a table takes place, which is the main distinction between a trigger and a procedure. On the other hand, a stored procedure must be called directly.

The following are the key differences between triggers and stored procedures:

1. Triggers cannot be manually invoked or executed.
2. There is no chance that triggers will receive parameters.
3. A transaction cannot be committed or rolled back inside a trigger.

Syntax:

create trigger [trigger_name] 

[before | after]  

{insert | update | delete}  

on [table_name]  

[for each row]  

[trigger_body] 

Explanation of Syntax

1. Create trigger [trigger_name]: Creates or replaces an existing trigger with the trigger_name.
2. [before | after]: This specifies when the trigger will be executed.
3. {insert | update | delete}: This specifies the DML operation.
4. On [table_name]: This specifies the name of the table associated with the trigger.
5. [for each row]: This specifies a row-level trigger, i.e., the trigger will be executed for each affected row.
6. [trigger_body]: This provides the operation to be performed as the trigger is fired