docs.intersystems.com
Home  /  Application Development: Core Topics  /  Class Definition Reference  /  Property Keywords  /  Cardinality


Class Definition Reference
Cardinality
[Back]  [Next] 
InterSystems: The power behind what matters   
Search:  


Specifies the cardinality of this relationship property. Required for relationship properties. Not used for other properties.
Usage
To specify the cardinality of a relationship property, use the following syntax:
Relationship relname As classname [ Cardinality = cardinality; inverse = inverse ];
Where cardinality is one of the following:
Details
This keyword specifies the cardinality of a relationship property.
The Cardinality keyword is required for relationship properties. It is ignored by non-relationship properties.
For more information on relationships, see Defining and Using Relationships in Defining and Using Classes.
Default
There is no default. When you define a relationship, you must specify the Cardinality keyword.
Example
Relationship Chapters As Chapter [ Cardinality = many; inverse = Book ];
See Also