Mrs. Schneider May 2012How to create a conceptual schema (CS) diagram usingNIAM steps with an example ‘problem’IPT YEAR 12RELATIONAL DATABASE
NIAM STEPS1. State the elementary facts2. Draw the first draft conceptual schema (CS) diagram.3. Remove surplus entities and indicate derived facts.4. Add uniqueness constraints5. Add mandatory roles and cardinality constraints6. Check that conceptual schema can be populated by examples given
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.
PLANT DATAFor 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.
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.
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
Plant with Biological nameHasFlowering Time with descriptionPlant with Biological nameHasAppearance described by the picturePlant with Biological nameIs inPot Size with number
Combination (Plant – Pot Size)HasQuantity in Stock with numberCombination (Plant – Pot Size)HasTotal Value with $Pot Size with numberHasPrice with $
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.