36 Implementing an Advanced Application Using Processes, Rules, Events, and Reports
Before creating a logical data model, you need to clarify as many of the model requirements
as possible. A business user’s description might be incomplete or lacking information. Often,
business users provide only a general understanding of the business process in which they
are interested. Architects can provide a deeper understanding of these business processes in
order to collect missing information in order to construct a complete model and deliver the
value that is requested.
A logical data model is not linked to a database tool or technology. It describes what an
organization or a company wants to gather data about and documents the relationships
between this data. Logical data models are organized hierarchically and contain
objects such
as packages, entities, attributes, and other relationships.
3.4.2 Creating the WARRANTY logical data model
Logical data model objects are always set under a root package object, of which there is only
one. You can add additional packages under the root package to group similar objects. In this
example the root package is the data design project created in 3.3, “Creating the data design
project” on page 34.
Now you will create the WARRANTY logical data model.
Create a logical data model
First you need to create a logical data model:
1. From the toolbar, select File New Logical Data Model (Figure 3-6)
Figure 3-6 New logical data model
The New Logical Data Model wizard opens. Create your model using the blank logical
data model template. If you created other templates previously, they would have been
available for you to select as the basis for this logical model. You can enable the template
for selection by specifying the location of the template file in the Template folder field.
Note: You can access these options by right-clicking in any empty area of your
workbench.
Chapter 3. Data modeling with InfoSphere Data Architect 37
2. Next, you need to name your data model. We suggest naming it
ITSO_WARRANTY_Logical_Data_Model, as shown in Figure 3-7. When done, click Finish.
Figure 3-7 New logical data model
3. The logical data model is created under the data design project. Should you want to name
your logical data object properties, right-click the logical data model object in the Data
Project Explorer and select Rename. After entering a suitable name in the New Resource
Name field, click OK to save your logical data model.
Create entities and attributes in the diagram
Now create entities in the diagram and define attributes for each:
򐂰 An
entity is a logical data model object that stores information about areas that are of
interest to business users.
򐂰 Each entity contains
attributes that describe details about the entity.
For example, you can create a CUSTOMER INFO entity that contains the CUSTOMER ID,
CUSTOMER FIRST NAME, and CUSTOMER LAST NAME attributes, which provide details
about a customer. When the logical data model is transformed into a physical data model,
these entities become
tables and the attributes become columns.
38 Implementing an Advanced Application Using Processes, Rules, Events, and Reports
Add entities to the diagram
To add an entity to your logical data model diagram:
1. Expand the Data Models folder to expose your logical data model diagram (Figure 3-8).
Figure 3-8 Open the logical diagram
2. Click Entity in the palette, and then provide the location in the diagram where you want to
add it.
3. You will want to name this entity something meaningful, such as PRODUCT INFO or CUSTOMER
INFO.
Add attributes to an entity
An entity can have attributes, such as primary keys and non-key attributes. To add attributes
to an entity:
1. Select the entity in the diagram to open the Properties view.
2. Select the Attributes tab under the Properties view, and then click New to add your
attribute.
3. You can also adjust other properties, such as Name, Primary Key, or Type, from the
Properties view.
Create the entities for the WARRANTY logical data model
Now, create the entities for the WARRANTY logical data model. In the palette view, expand
the Data section. Next, drag six entities into any blank area in the diagram editor and name
each as follows:
򐂰 CUSTOMER INFO
򐂰 PRODUCT INFO
򐂰 WARRANTY LEVEL INFO
򐂰 WARRANTY STATUS INFO
򐂰 CUSTOMER PRODUCT SALES
򐂰 WARRANTY TRANSACTIONS

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