1. Mrs. Schneider
May 2012
How to create a conceptual schema (CS) diagram using
NIAM steps with an example ‘problem’
IPT YEAR 12
RELATIONAL DATABASE
2. NIAM STEPS
1. State the elementary facts
2. Draw the first draft conceptual schema (CS)
diagram.
3. Remove surplus entities and indicate derived
facts.
4. Add uniqueness constraints
5. Add mandatory roles and cardinality
constraints
6. Check that conceptual schema can be
populated by examples given
3. BUSINESS ‘PROBLEM’
Nurture Nursery
specializes in native
plants. The business
requires a computerised
system that includes
functionality for
inventory control and
production of
identification tags.
4. PLANT DATA
For each plant the system will need to store:
biological name
common name
maximum growth height in metres
colour of flowers
the time of year for flowering
picture of the plant.
The identification tags will need to carry all this
information.
5. MORE INFORMATION
The plants are sold in four pot sizes (1 to
4), which have a corresponding retail price
($4, $5, $6, $8). The number of each plant in
each pot size will also need to be stored.
The nursery requires a simple way of
updating stock numbers when plants are sold
or stock replenished. The new stock most
often comes in orders of a particular
plant, but the business sometimes
replenishes all stock by ordering a set
quantity of all No. 1 size pots.
6. STATE THE ELEMENTARY FACTS
Plant with Biological name
Has
Common Name of
Plant with Biological name
Has
Maximum Height with metres
Plant with Biological name
Has
Flower Colour with description
7. Plant with Biological name
Has
Flowering Time with description
Plant with Biological name
Has
Appearance described by the
picture
Plant with Biological name
Is in
Pot Size with number
8. Combination (Plant – Pot Size)
Has
Quantity in Stock with number
Combination (Plant – Pot Size)
Has
Total Value with $
Pot Size with number
Has
Price with $
13. WHAT IS NEXT IN THIS PROCESS?
After creating the conceptual schema you
would
start to create table definitions (planning how you
will create the tables)
Draw draft forms (interfaces)
Possibly create an information flow diagram
Create the database within Access, Oracle etc.
