From the course: Querying Microsoft SQL Server 2012

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An introduction to relational theory

An introduction to relational theory - SQL Server Tutorial

From the course: Querying Microsoft SQL Server 2012

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An introduction to relational theory

In this video, we'll take a look at relational theory that takes its roots from mathematical concepts. We'll describe what relational is as it pertains to database systems and how this impacts the use of T-SQL for querying the database, as well as your own thought process when writing T-SQL queries. The relational model is actually based on mathematical concepts. It includes considerations around things known as set theory, predicate logic, and attributes. Set theory is based on the concept of a set. A set is essentially a collection of distinct objects. The keys on your key ring might be a set. We refer to them as a set of keys. The students in a classroom are considered a set. But it's also important to note that from the mathematical perspective, each item in a set is distinct, which means there can be no duplicates. So the analogy of keys on the key ring will be considered a set as long as no keys are duplicate on that key ring. The analogy of students in a classroom is a much…

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