Lecture 32: Introduction to 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
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Lecture 31 – Combining Results with UNION
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
Lecture 30: Mini-Project – Querying the Blog
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
Lecture 29 – Mini-Project: Populating the Blog
This lecture covers populating the blog database with sample data.Our blog database structure is built, but it’s an empty shell. To make things interesting, we… Read More »Lecture 29 – Mini-Project: Populating the Blog
Lecture 28: Mini-Project – Creating the Blog Tables
Learn Databases: Lecture 28 – Mini-Project: Creating the Blog Tables.This lecture covers the SQL implementation of the blog database design. In the last lecture, we… Read More »Lecture 28: Mini-Project – Creating the Blog Tables
Lecture 27: Mini-Project – Blog Database Design
This lecture begins the design of a multi-table blog database. It’s time for our most ambitious project yet. We are going to design a database… Read More »Lecture 27: Mini-Project – Blog Database Design
Lecture 26: Simplifying Queries with Table Aliases
This lecture covers using table aliases to simplify queries. In our last few lectures, we wrote queries that joined tables. You probably noticed that we… Read More »Lecture 26: Simplifying Queries with Table Aliases
Learn Databases: Lecture 25 – The LEFT JOIN
This lecture covers the LEFT JOIN. In the last lecture, we saw that an INNER JOIN only returns rows where a match is found in both tables.… Read More »Learn Databases: Lecture 25 – The LEFT JOIN
Lecture 24: Combining Tables with INNER JOIN
This lecture covers the INNER JOIN to combine data from multiple tables. We have created separate `Customers` and `Orders` tables and linked them with a… Read More »Lecture 24: Combining Tables with INNER JOIN
Lecture 23: Linking Tables with Foreign Keys
This lecture introduces the concept of Foreign Keys. If the primary key is the anchor of a table, the foreign key is the chain that links it… Read More »Lecture 23: Linking Tables with Foreign Keys