Chapter 8 DATA MODELING:
The information flow defined as part of the business-modeling phase is refined into a set of data objects that are needed to support the business. The characteristics (called attributes) of each object are identified and the relationships between these objects defined.
In our project first we concentrate to establish the following points
Ø Data objects
Ø Attributes
Ø Relationship
Data object:
In this project the data object is a representation of any composite information that must be understand by software. By COMPOSITE INFORMATION, we mean something that has a number of different properties or attributes. Data object can be external or internal (i.e., anything that produce or consumes information) data object encapsulates data only –there is no reference within a data object to operations that act on the data. Therefore the data object can be represent as a table as bellow. The heading is the table reflects attributes of the object .in this case, a product is defined in term of make part no, code, warrantee.
TABULAR REPRESENTATION OF DATA OBJECT
Attributes:
Attributes define the properties of a data object. Attribute names, describe its characteristics, and in some cases, make reference to another object.
Relationships:
Relationships indicate the manner in which data object are “connected” to one another. Now we will explain the relation with the help of our project component for example we consider two data object, product and Medical Store. These objects can be represented using the simple notation as bellow:
CONNECTION BETWEEN OBJECTS
I have used more than one connection in our project for the following reason:
Ø Medical Store orders the Medicine
Ø Medical Store display Medicine
Ø Medical Store stock Medicine
Ø Medical Store sell Medicine
Ø Medical Store purchase Medicine
Ø Medical Store return Medicine
The relationship as follows:
ORDER
RELATIONSHIP BETWEEN OBJECTS
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