Frequent question: Are triggers good SQL?

Triggers can be a good choice if there is an external tool that access and inserts data to your database and you cannot access to code, but you need to add some functionality on insert, delete and update clauses.

Is it good to use triggers in SQL?

Triggers are useful if you need to be sure that certain events always happen when data is inserted, updated or deleted. This is the case when you have to deal with complex default values of columns, or modify the data of other tables. You can use external code as a trigger by using CLR triggers.

Are triggers bad for SQL Server?

Triggers are generally over-used in SQL Server. They are only rarely necessary, can cause performance issues, and are tricky to maintain If you use them, it is best to keep them simple, and have only one operation per trigger.

Is it good practice to use triggers?

Using remote queries in triggers is a bad practice. Distributed queries have detrimental effects on performance and you should avoid this practice if possible. In the case you have to implement referential integrity between databases residing on different servers try to keep the usage of remote queries to a minimum.

THIS IS IMPORTANT:  Question: Who invented Java language and in which year?

Why we should not use triggers in SQL?

The general consensus here is that triggers are indeed harmful. Because they change the well known semantics of an INSERT, UPDATE or DELETE statement.

Why you shouldn’t use triggers?

They are also the best place for auditing unless you don’t want to capture all changes to the database (which is the problem of auditing from the application). Triggers can cause performance issues if not written carefully and not enough developers are knowledgeable enough to write them well.

Are SQL triggers slow?

Lags. A trigger fires inside the transaction that modifies the data in the table. … The triggers of this type will not slow down operations, however, will ensure data coupling and integrity. Every time I experienced “lags” when adding data to a table with a trigger, it was an example of such a “heavy” query.

What can SQL triggers do?

A SQL trigger is a database object which fires when an event occurs in a database. We can execute a SQL query that will “do something” in a database when a change occurs on a database table such as a record is inserted or updated or deleted. For example, a trigger can be set on a record insert in a database table.

What is instead of trigger SQL Server?

An INSTEAD OF trigger is a trigger that allows you to skip an INSERT , DELETE , or UPDATE statement to a table or a view and execute other statements defined in the trigger instead. The actual insert, delete, or update operation does not occur at all.

Which SQL trigger does SQL Server not support?

SQL Server triggers only fire once per query, so they are set triggers rather than row triggers. SQL Server does not support select triggers.

THIS IS IMPORTANT:  How does var work in Java?

What are trigger best practices?

Apex Trigger Best Practices

  • One Trigger Per Object. We should write only 1 Trigger per Object. …
  • Follow Naming Convention. …
  • Use only Required Events in Trigger. …
  • Context-specific Handler Methods. …
  • Logic-less Triggers. …
  • Bulkification. …
  • Use Collections and Avoid SOQL or DML in FOR loops. …
  • Use SOQL Query FOR Loop.

Can we fire a trigger manually?

Triggers cannot be manually executed by the user. There is no chance for triggers to receive parameters.

What is the difference between trigger and stored procedure?

A stored procedure is a user defined piece of code written in the local version of PL/SQL, which may return a value (making it a function) that is invoked by calling it explicitly. A trigger is a stored procedure that runs automatically when various events happen (eg update, insert, delete).

Why do we need triggers in database?

Triggers help the database designer ensure certain actions, such as maintaining an audit file, are completed regardless of which program or user makes changes to the data. The programs are called triggers since an event, such as adding a record to a table, fires their execution.

What is the alternative for triggers?

One alternative you might want to look into are computed columns in SQL Server. If that matching is a pretty straightforward one (e.g. extract the character 10 through 14 from the string) or something like that, you could create a computed column to do so automagically – no trigger needed.

What are database triggers used for?

A database trigger is procedural code that is automatically executed in response to certain events on a particular table or view in a database. The trigger is mostly used for maintaining the integrity of the information on the database.

THIS IS IMPORTANT:  Best answer: What is logon trigger in SQL Server?