CHAPTER 1
Background to T-SQL Querying and Programming
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The goal of the relational model is to enable consistent representation of data with minimal or no
redundancy and without sacrificing completeness, and to define data integrity (enforcement of data
consistency) as part of the model. An RDBMS is supposed to implement the relational model and pro-
vide the means to store, manage, enforce the integrity of, and query data. The fact that the relational
model is based on a strong mathematical foundation means that given a certain data model instance
(from which a physical database will later be generated), you can tell with certainty when a design is
flawed, rather than relying solely on intuition.
The relational model involves concepts such as propositions, predicates, relations, tuples, attri-
butes, and more. For non-mathematicians, these concepts can be quite intimidating. The sections
that follow cover some of the key aspects of the model in an informal, nonmathematical manner and
explain how they relate to databases.
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