HTML and CSS Reference
In-Depth Information
Constructing Data Model
Let's start with creating the data model of Mega App. Figure
13-13
shows the Mega App logical data model.
Figure 13-13.
Mega App logical data model
As shown in the diagram, Mega App data model contains four entities:
1.
BOOK Entity
:
BOOK
entity is responsible for storing the topic data. It has the attributes
shown in Table
13-1
.
Table 13-1.
Book Entity Attributes
Attribute name
Logical Type
Nullable
Description
ID
Integer
Primary Key (NOT NULL)
Auto-generated ID that
represents book ID
ISBN
String(64)
NOT NULL
Book ISBN
TITLE
String(128)
NOT NULL
Book title
AUTHOR
String(128)
NOT NULL
Book author
PUBLISHER
String(64)
NOT NULL
Book publisher
LANG
String(64)
NOT NULL
Book language
CONTENT
Bytes(1 MB)
NOT NULL
Book content
