SQL Server Tutorial : Building and Optimizing Triggers in SQL Server

Want to learn more? Take the full course at https://learn.datacamp.com/courses/building-and-optimizing-triggers-in-sql-server at your own pace. More than a video, you'll learn hands-on coding & quickly apply skills to your daily work. --- Hi! My name is Florin Angelescu and I will be your instructor for this course on Building and Optimizing SQL Server Triggers. After completing this course, you will feel confident implementing and using triggers in your day-to-day tasks. Let's get started! A trigger is a special type of stored procedure that is automatically executed when events (like data modifications) occur on the database server. In terms of Transact-SQL (T-SQL) commands, there are three types of trigger in SQL Server: * Data Manipulation Language (DML) triggers are executed when a user or process modifies data through an INSERT, UPDATE, or DELETE statement. These triggers are associated with statements related to tables or views. * Data Definition Language (DDL) triggers fire in response to statements executed at the database or server level, like CREATE, ALTER, or DROP. * Logon triggers fire in response to LOGON events when a user's session is established. We will cover all these trigger types in more detail in later lessons. Another way to classify triggers is based on their behavior. A trigger can behave differently in relation to the statement that fires it, resulting in two types of triggers. The first type, an AFTER trigger, is used when you want to execute a piece of code after the initial statement that fires the trigger. An example use case of this type of trigger is to rebuild an index after a large insert of data into a table. Another example is using a trigger to send alerts when UPDATE statements are run against the database. You'll see more examples as you progress through the course. The second trigger type is the INSTEAD OF trigger. As its name suggests, an INSTEAD OF trigger will not perform the initial operation, but will execut