Chapter-01

basesprocketΔιαχείριση Δεδομένων

31 Οκτ 2013 (πριν από 3 χρόνια και 9 μήνες)

106 εμφανίσεις

1
-
1



David M. Kroenke and David J. Auer

Database Processing

11
th

Edition

Fundamentals, Design, and Implementation




Chapter 1:

Introduction

Must read the chapter for complete information.




1
-
2


Chapter Objectives


To understand the nature and characteristics of
databases


To gain a general understanding of tables and
relationships


To describe the components of a database system


To understand database design: from existing data or as
new system development.


To understand database re
-
design.

1
-
3


The Characteristics of Databases


The purpose of a
database

is to help users track things
of interest to them.


Data is stored in
tables
, which have rows and columns
like a spreadsheet.


A database may have multiple tables, where each table
stores data about a different thing (data object).


Each row in a table stores data about an occurrence or
instance

of the data object.


A database stores
data

and
relationships
.


Tables should not contain
redundant

data.


Relationships are expressed thought
Foreign

keys.

1
-
4


Data in Tables

1
-
5


Related Tables

1
-
6


Naming Conventions (in this Textbook)


Table names

are written with all capital letters:


STUDENT, CLASS, GRADE


Column names

are written with an initial capital letter:


Term, Section, Age, Salary


Compound names

are written with a capital letter on
each word:


CourseTitle, ClassNumber, StudentName


1
-
7


Databases Create Information


Data

= recorded facts and figures.


Data items must be used in "context" for meaningful use.


Data items must be "process
-
able" or "manipulate
-
able".



Information

= knowledge derived from data.


Databases record data, but they do so in such a way that
we can
produce information

from the data.



The data on STUDENTs, CLASSes, and GRADEs
could produce information about each student’s GPA.


(see next slide)

1
-
8


Databases Create Information

1
-
9


Components of a Database System

SQL: Structured Query Language)

1
-
10


Applications, DBMS, and SQL


Applications

are the computer programs that users work
with.


The
Database Management System (DBMS)

creates,
processes, and administers databases.


Structured Query Language (SQL)

is an internationally
recognized standard
database language

that is used by
all commercial DBMSs.

1
-
11


Database Applications

1
-
12


Database Applications
-

Forms

Data Entry Form

1
-
13


Database Applications
-

Queries

SELECT


LastName, FirstName, EmailAddress

FROM STUDENT

WHERE StudentNumber > 2;

SQL Query Example

1
-
14


Database
-

Reports

Query output example (report)

1
-
15


The DBMS (DB Engine)

1
-
16


The Database


A
database

is a collection of integrated tables.


The tables are called
integrated

because they store data
about the
relationships

between the rows of data.


A database is called
self
-
describing
because it stores a
description of itself.


The self
-
describing data is called
metadata
, which is
data about data (table columns).

1
-
17


Typical Metadata Tables

1
-
18


Prominent DBMS Products


Microsoft
-

MS Access


Microsoft
-

SQL Server 2012 (most recent)


Microsoft SQL Server 2008 R2 Express (for this class)


Oracle Corporation
-

Oracle Database


Sun Microsystems
-

MySQL 5.1


IBM
-

DB2

1
-
19


DBMS Power vs. Ease of Use

1
-
20


Enterprise
-
Class Database Systems

1
-
21


Microsoft Access


Microsoft Access is a
low
-
end product

intended for
individual users

and small workgroups.


Microsoft Access is
simple and easy to use
. It tries to
hide much of the underlying database technology from
the user.


A good strategy
for beginners
, but not for database
professionals.


The Microsoft Access DBMS engine is called
Jet
, which
is not sold as a separate product.


NOTE:

Microsoft Access 2007 is discussed in detail in
Appendix A (online).

1
-
22


Personal Database Systems:

Microsoft Access

1
-
23


Database Design: Three Types

1
-
24


Option 1:

Database Design from Existing Data

1
-
25


Data Import Issue:

One or Two Tables?


This is an important
decision. It is based on
a set of rules known as
normalization

(covered
in Chapter 3).

1
-
26


Option 2:

Database Design from New System Development

Entity
-
Relationship Data modeling

is covered in Chapter 5, and data model
transformations to database designs are covered in Chapter 6.

1
-
27


Option 3:

Database Redesign

Database redesign is
covered in Chapter 8,
after the coverage of
SQL in Chapter 7
(mainly creating and
altering tables).

1
-
28


A Brief History of
Database Processing


(Self Reading)

1
-
29


End of Chapter 1 Slides