Join Operations
Learn how to connect and compare tables using different join types and the Division operator, expressed through relational algebra.
We'll cover the following...
Imagine our OnlineStore is going very well and we want to see the name of every product along with its supplier’s name. But these two pieces of information live in separate tables: Products and Suppliers. How do we bring this information together? This is where join operations come into play. Join operations are the backbone of relational databases, allowing us to connect data across multiple tables to answer complex questions that a single table alone cannot.
By the end of this lesson, we will be able to:
Understand why joining tables is a fundamental concept in relational databases.
Differentiate between various types of joins, including the
Theta Join,Equi Join, andNatural Join.Grasp the purpose and application of the
Divisionoperator for “for all” type queries.Express these operations using formal relational algebra notation.
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The power of combining data with joins
In a well-designed relational database, data is organized into multiple tables to avoid redundancy and improve data integrity. For instance, in our OnlineStore database, we have a ...