This lecture covers data integrity constraints. Data integrity refers to the accuracy, consistency, and reliability of data stored in a database. We want to prevent bad… Read More »Lecture 39: Ensuring Data Integrity with Constraints
This lecture covers handling NULL values. In the real world, data is often incomplete. A customer might not have a phone number, or a post… Read More »Lecture 38 – Handling Missing Data with NULL
This lecture introduces database indexes. Imagine trying to find a specific topic in a book that has no index at the back. You would have… Read More »Lecture 37: Speeding Up Queries with Indexes
This lecture covers Third Normal Form (3NF). We’ve covered 1NF (atomic values) and 2NF (no partial dependencies). The final normal form we will discuss in… Read More »Lecture 36: Third Normal Form 3NF
This lecture covers Second Normal Form (2NF). Once a table is in First Normal Form (1NF), the next step is to check if it satisfies… Read More »Lecture 35: Second Normal Form 2NF
This lecture introduces the concept of database normalization and First Normal Form (1NF). Database Normalization and 1NF When we designed our blog database, we intuitively… Read More »Lecture 34: Database Normalization and 1NF
This lecture covers more advanced uses of subqueries. In the last lecture, we saw how subqueries can be used in the WHERE clause. Now let’s explore two… Read More »Lecture 33: Advanced Subqueries
This lecture introduces the concept of subqueries. We are now moving into Part 4 of our series: Advanced Concepts. The first of these is the subquery,… Read More »Lecture 32: Introduction to Subqueries
This lecture covers the UNION and UNION ALL operators. So far, we have only worked with the results from a single SELECT statement at a time (even… Read More »Lecture 31 – Combining Results with UNION
This lecture covers querying the blog database with joins. Our blog database is designed, created, and populated. Now we get to the payoff: asking complex… Read More »Lecture 30: Mini-Project – Querying the Blog