Lectures

In this lecture, you'll find out what triggers are in databases, how they work, why they're used, their pros and cons, and you'll see real-life examples of using triggers for automation, logging, and keeping your data consistent.

In this lecture, you'll learn about the three main types of triggers in PostgreSQL: BEFORE, AFTER, and INSTEAD OF. We'll break down when and why you use them, how to implement typical scenarios with code examples, and also look at the quirks and limitations of each trigger type.

In this lecture, you'll learn how to create triggers in PostgreSQL: we'll break down the CREATE TRIGGER syntax, working with WHEN conditions, linking with EXECUTE FUNCTION, and also check out practical examples and common mistakes when working with triggers.

In this lecture, you'll learn how to create a BEFORE INSERT trigger in PostgreSQL to automatically fill the last_modified field when new records are added. We'll break down how to create a function for the trigger, the trigger itself, testing, common mistakes, and practical use cases.

In this lecture, you'll learn how to use the special variables OLD, NEW, and TG_OP inside trigger functions in PostgreSQL. We'll break down, with hands-on examples, how to track data changes, log operations, and avoid common mistakes when working with triggers.