Select SSADM Professional
Index
Select SSADM Professional .......................................................................................... 1
Index .............................................................................................................................. 1
Introduction .................................................................................................................... 2
Set up a project............................................................................................................... 2
Data Flow Diagram ........................................................................................................ 4
Defining Data Flows ...................................................................................................... 8
Adding ERDs to an existing project ............................................................................ 10
Generate a Physical Data model .................................................................................. 15
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Introduction
This product allows users to document projects. Each project is set up separately, in a
different directory.
Set up a project.
To run Select SSADM, select it from the Start menu.
You may need to add a license number. If so, choose the ‘Maintenance’ option and
‘Add License’. Your lecturer or tutor will give you the appropriate license number.
1.
What is a project? It is a single repository, complete with diagrams and
dictionary descriptions.
2.
Where should my project be held? The project should be held in it’s own
directory on a medium to which the project owner has private write access
– i.e. not the C: drive in the labs. Use a directory name that is or includes
your username, so that it will not be confused with other projects. Include
your full name in the project title.
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3.
How do I do my diagrams? To set up a new diagram a project must first
be set up. To do this, choose Project and New.
Give your project a title and directory as specified in 3. To start a diagram,
choose
the
blank
document icon on the
standard toolbar. The
default diagram type is
CCD, but this is
probably not the type of
diagram you want. Use
the drop down box to
change the type. Name
the file appropriately.
When the project has been successfully created, with at least one diagram,
the title of the project should appear in the bottom information bar.
4.
5.
How do I save my project? When you close the application, the files are
saved in the directory that you have given. The directory is logged by that
workstation as having a project.
How do I reopen my project? If you open the application from that
workstation, you can open a diagram. This will prompt you with a project
selector that shows you what projects are recognised by it. If your project
has not been used from that workstation before, set it up as a new project,
using the same directory as previously. This will pick up your repository.
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Data Flow Diagram
How do I start a context diagram? A context diagram is a type of DFD, so choose
DFD and specify context diagram on the next form.
How do I add things to my diagram? Right click on the diagram to add external
entities, etc. If you are adding something that has been used before, use the browse
facility, to reuse the existing object. All items are put into the dictionary. More
information can be added to your description of an existing item by double clicking
on it for the editor, or right clicking and choosing the appropriate action.
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How much information do I need to include? The same as you would when drawing
the diagram by hand. Your drawing should be complete and any definitions that you
have added to the dictionary should be adequately, but not overly described.
How do I add my DFD to my system? While in the context diagram, right click on
the context box, click child diagram, DFD and Open. This will bring all your data
flows from the context down to the level-1 DFD.
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How do I add a location to a process box? Select the process box (see below) and
right click.
Select one of the links available, or add one – e.g. Joe’s office
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Click OK, then Add the location as the process link
The result:
5
Joe's Office
Produce
financial
report
*
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Copyright Patricia O’Byrne School of Computing
Defining Data Flows
Data flows are made up of the data items that are in them. To add a data item to a
data flow, first define the data item. This can be done through the Dictionary.
Choose Dictionary on the top toolbar and Populate. From the menu, choose Data
Item and Add.
Enter the data items. The name should not include any spaces. Convention suggests
that it should have an upper case first letter for each word, with the rest lower case.
If you wish, you can add a description. When you are finished, click OK. The editor
clears to allow you to enter a new data item. When you have added all the necessary
data items, click Ok to exit the editor.
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To add a data item to a data flow, right click on the data flow and choose Links, then
‘Data flow consists of Data Item’. The following menu appears:
Continue to add fields as links to the Data Flow
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Copyright Patricia O’Byrne School of Computing
This defines the data flow.
Adding ERDs to an existing project
3.
How do I open my project?
Presumably, you have stored your project on a medium to which you alone
have access, such as your F: drive, or a floppy or zipped disk. Choose New
diagram from the File menu, or click the blank sheet icon. Click the Project
button
to
select
your
own
project.
Choose LDS as the Type of diagram.
LDS stands for Logical Data Structure.
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NOTE!!: If your project does not appear on the project list, then you
need to register your project on the machine on which you are working.
To do this, Cancel your current operation and click Project and New. Give
your project THE SAME title and directory as before. When the project has
been successfully “created”, all of the diagrams you have already done will be
accessible
to
you.
2. Once your diagram has been created, you will be working on a blank diagram
as shown below.
3. To add an entity, right click in free space and choose Entity. You will be
prompted as follows:
You need only add the entity name. The aspect refers to the point of view from which you are
modelling the entity. We assume that we are modelling from a ‘birds-eye’ view.
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4. To add attributes to the entity, right click on the entity and choose edit.
Ignore the tick boxes at the bottom and the top, for the moment.
NOTE!!: The tick boxes ‘Prime Key’, ‘Optional’ and ‘Allow Key Inheritance’
will have a significant effect on your diagram. The ‘Foreign Keys…’ button will
also become significant.
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5. To add a relationship:
Select the originating entity. Right click on it and a line from the entity will
trail your cursor. Click on the destination entity to complete the relationship.
The default type will be one to many. Right click on the relationship and
choose Edit.
You may change the multiplicity of your relationship here.
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NOTE!!: The ‘Allow master to detail propagation’ tick box, if ticked,
imports the key from the ‘one’ entity into the ‘many’ entity.
By making the attribute ‘Dog Breed’ a primary key in the originating entity and ticking this
tick box, ‘Dog Breed’ appears as a foreign key in the destination entity. Note also that this
example is rubbish.
If you find that phantom attributes are being added to your entities, this may
be because you altered the relationship. In the following example, I deleted the
relationship and added it again as a new relationship. It generated the foreign key
again, putting in a 1 at the end of it.
To correct this, delete any propagated keys before changing the relationship.
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Generate a Physical Data model
1. Open a new diagram of type Physical Data Model. From the tools menu, choose
LDM to PDM mapping and say Yes to ‘Do you wish to proceed?’ Use the
defaults offered for Aspects and Super/Sub-types.
2. After the tables are generated, right click on the empty diagram. Choose ‘Add
tables / relationships’.
This will automatically populate your diagram with
tables.
3. To see all your tables, use the bottom and side scroll bars to reach the invisible
tables. When you get to the edge, you are prompted to extend the edge.
4. To see all the attributes, choose ‘View’ and ‘View options’ and ‘show all’. Then
click ‘view override’ to show attributes.
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5. Edit each attribute to give it a data type. To do this, select the table, right click
and Edit. When the table comes up, select the attribute that you want to define
and click Edit.
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6. When all of the attributes have been given data types, the tables are ready for
generation.
Go back to the tools menu and choose SSADM SQL Schema
Generator. When the following screen shows, you must select the tables that you
want to generate, and select your Target Environment. Generate SQL to create
the tables. If you want to keep the generated SQL, you must save it.
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