This document discusses different types of attributes in database design. It describes attributes as properties that describe entities. There are several types of attributes including composite vs simple, single vs multi-valued, stored vs derived, and complex attributes. Composite attributes can be divided into sub-parts while simple attributes cannot. Single-valued attributes have one value per entity, while multi-valued attributes can have multiple values. Null values represent the absence of a data item. Complex attributes group composite and multi-valued attributes.

1. Attributes are properties of interest that
further describe the entity
TYPES OF ATTRIBUTES
 COMPOSITE VS SIMPLE ATTRIBUTES
 SINGLE VALUE VS MULTI-VALUED
ATTRIBUTES
 STORED VS DERIVED ATTRIBUTES
 NULL VALUES
 COMPLEX ATTRIBUTES

2. COMPOSITE VS SIMPLE
ATTRIBUTES
 Composite attributes can be divided into
smaller sub-parts to represent some more
basic attributes Eg. Name of a person –
composite(first name, second name etc.)
 Simple attributes can not be sub divided
Eg. Height of a person

3. SINGLE VALUE VS MULTI-VALUED
ATTRIBUTES
An attribute with a single value for an entity
is single –valued as opposed to those
with multiple values
Eg.Height of a person-single valued
Qualification of a person- multi valued
attributes

4. Null values
Absence of a data item is represented
by a special value called null value

5. Complex attributes
The composite and multi–valued
attributes may be grouped to
constitute complex attributes

6. Any attribute which contains unique
values for identifying the entity
instance is known as identifier
Eg.roll no of a student

7. It refers to a set of techniques
that are used to design a data
base. These techniques use
certain concepts which are crucial
to the creation of structure and
development of the design

8. The relational data model represents the
database as collection of relations ,which
resembles a table of values
row – tuple( an ordered set of values)
column header- attribute
table –relation
data type describing the types of values-
domain
domain is a set of indivisible values

9. ACCOUNTING SYSTEM USING
DATABASE MANAGEMENT
SYSTEM
Query- a request for information from a
data base
SQL-Structured Query Language
SQL is used to communicate with a
data base

10. Simple query
A query which does not involve use
of any query function to produce a
summary of data
TYPES OF QUERIES

11. Parametre query
A parameter query prompts the user
to enter parameters, or criteria
through an input box for selecting a
set of records
TYPES OF QUERIES

12. Summary query
A summary query is used to
extract aggregate of data items
for a group of records rather than
a detailed set of records
TYPES OF QUERIES