Chapter 2 Conceptual Data Model Basics
You can choose to use one or both of the following notation types in the current model:
| Option | Description | Symbols |
|---|---|---|
| Entity / Relationships | Entity/relationship notation connects entities with links representing one of four relationships between them. These relationships have properties that apply to both entities involved in the relationship | 
|
| Merise | Merise notation uses associations instead of relationships | 
|
| E/R + Merise | Both entity/relationship and Merise are used in the same model | Both types of symbols |
| IDEF1X | Data modeling notation for relationships and entities. In this notation, each set of relationship symbols describes a combination of the optionality and cardinality of the entity next to it | 
|
The Entity / Relationships notation is the default notation used in this manual.
When you change notation, all symbols in all diagrams are updated accordingly.
Entities display rounded rectangles when they depend on another entity either through an inheritance link or when the relationship has the dependent property selected.
Relationships: unlike the other notations, relationship symbols cannot be parsed in terms of optionality and cardinality independently. Each set of symbols describes a combination of the optionality and cardinality of the entity next to it.
| Cardinality | Representation |
|---|---|
| One - Many | 
|
| One - One or Many - Many | 
|
| One - One dependent displays a continuous line and entity with rounded angles | 
|
PowerDesigner does not support the following notation:
or
Sub-type or inheritance symbol changes according to the Complete property:
| Complete | Symbol |
|---|---|
| Yes | 
|
| No | 
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