Notation Settings for PowerDesigner Concept Models

When designing a database model, it is divided into two types: conceptual model design and physical model design. The conceptual model mainly reflects the business relationship in the real world, that is, the entity relationship diagram we commonly use. The physical model is generated by direct conversion of the conceptual model after the conceptual model is designed, and then the physical model generated by the system is modified. The modeling of the conceptual model mainly depends on the business understanding ability of the modeler, while the modeling of the physical model mainly depends on the modeler's familiarity with a database product and the relevant technical level.
Create a new conceptual data model in PowerDesigner, and you can select the Notation of the model. In PD15, there are 5 kinds of Notations to choose from. After creating a conceptual model, right-click in the design panel, and select the "Model Options" option in the pop-up menu. You can pop up the model option window and modify the Notation of the model, as shown:



Generally, we use the ER diagram as the conceptual model diagram, so it is recommended to choose Entity/Relationship or E/R+Merise. The difference between the two is that the latter is in the ER model. The Merise modelling theory is also provided at the base, allowing the use of Association and Association Link in conceptual models. In the other three Notations, Merise uses Association to completely replace Relationship; IDEF1X is an extended version of IDEF1 in IDEF series methods. This method is slightly different from the general ER diagram representation; Barker is more simplified than the ER model, and can only use the "entity" and "relationship" components for modeling, and cannot use the "inheritance" component. In general, it is enough to use the E/R model, but in order to better represent the business relationship between entities, sometimes it is necessary to use Association instead of entities, so it is more recommended to choose E/R+Merise Model.