Database Reference
In-Depth Information
CHAPTER 3
OF
D
ATA
M
ODELS
Now that you have a grasp of the logical elements used to construct a data
model, let's look at the physical elements. These are the objects that you
use to build the database. Most of the objects you build into your physical
model are based on objects you created in the logical model. Many physi-
cal elements are the same no matter which RDBMS you are using, but we
look at all the elements available in SQL Server 2008. It is important to
know SQL Server's capabilities so that you can build your model with them
in mind.
In this chapter, we cover all the physical SQL Server objects in detail
and walk you through how to use each type of object in your physical
model. You will use these elements later in Chapter 9.
First, we'll start with the objects that allow you to store data in your data-
base. You'll build everything else on these objects. Specifically, these are
tables, views, and data types.
Tables
Tables are the building blocks on which relational databases are built.
Underneath everything else, all data in your database ends up in a table.
Tables are made up of rows and columns. Like a single instance in an en-
tity, each row stores information pertaining to a single record. For exam-
ple, in an employee table, each row would store the information for a
single employee.
The columns in the table store information about the rows in the table.
The FirstName column in the Employee table would store the first names
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