Introduction to Database Management System
unit will cover following topics:
of a database.
between relational database and file system.
of Relational Database.
for maintaining and retrieving data from a relational database.
the completion of this unit the learner will be able to :
database is a collection of related information. For example, a phone book is a
database of names,
addresses and phone numbers.
data file is a single disk file that stores related information on a hard disk
or floppy diskette.For
phone book database would be stored in a single data file.
Database Management System (DBMS) is a software tool that facilitates
creating, maintaining, and
manipulating an information database.
two types of DBMS
Relational database software allows the user to work with several database files at
the same time and
share information across the files. For
example, to implement an accounting database system, one
capabilities to link together information that is stored in the different files. An example of a relational database software would be Microsoft
Access, Oracle, Sybase and
flat-file database program, allows the user to create many databases but lets
file at a time. Using a flat -file database program, one can create simple
mailing list databases or personnel files.
of the database approach over traditional file-processing systems
Following are some of
the advantages of using a database over a traditional file-processing system:
for enforcing standards.
application development time.
of up-to-date information to all users.
of a Relational Database
are some of the advantages of a relational database:
can be easily accessed.
can be shared.
can be flexibility.
Data storage and redundancy
can be reduced.
can be avoided.
can be maintained.
can be enforced.
restrictions can be applied.
between physical storage and logical data design can be maintained.
High-level data manipulation language (SQL)
can be used to access and manipulate data.
A Relational database
stores data is tables. The data
stored in a table is organized into rows and columns. Each
row in a table represents an
individual record and each column represents a field. A
record is an individual entry in the database. For
example, each person’s name, address,
phone number is a single record of information in a phone book.
Whereas a "field" is a piece of information in a record.
example, you can divide a person’s record
in the phone book into fields for their last name, first name, address,
city and phone
query is a quick method provided by DBMS programs to search a database and retrieve
example, to find all the records from the phone book with last name Smith, the
will be as follows:
SELECT * FROM PhoneBook where LName = ‘SMITH’;
form is used to view all fields for one record at a time. It can also be used
data into the database. Following is an example of a form to enter information
related to the spelling words.
tool is used to extract data from the database and present the information in
the format that tables
and forms to do not easily permit.
example, reports can be used to group related record together and include summary
fields. Reports can be created in a
number of different presentation styles. Some
of the most popular design styles are tabular (the most common), single record,
and multi-record (for
Following is an example of a report listing the student's course,
level and total score.
Assignment: Read Chapter 1
Assignment: Select a topic
for the class project. Use worksheet
to submit the topic for the
the class project.