Cardinality Control in Link Rules

The Cardinality Values and Uses

In the latest release of Cradle using Cardinality in a cross reference has been introduced. This extends the capability of controlling cross references to the point of how many relationships an item can have.

The Many-to-Many Relationship

This is the default option for a rule when it is first set. This is also the default option when a rule is imported from an older version which does not have this option. This cardinality relationship is applied to:

  • Most of the link rules in the as-supplied Cradle demonstration databases DEMO and SYSM
  • Most of the link rules in the as-supplied default schema and quick-start
Demo Link Rules showing the Cardinality
Showing One to Many and Many to Many Cardinalities

The One-to-Many Relationship

This cardinality is used for parent-child relationships between items of the same type. Furthermore this option is applied to:

  • Parent-child link rules in the as-supplied Cradle demonstration databases DEMO and SYSM
  • Parent-child link rules in the as-supplied default schema default and quick-start

The Many-to-One Relationship

This option will allow many items linked down to a single item. Many users can be assinged to one Requirement.

The One-to-One relationship

This is mainly for links like a single result file to a single test file.

Link Rule Setup options
Showing the Cardinality option within the Link Rule Setup

The new cardinality option is for all item types which includes all the modelling types as well.

Hence if a user tries to set linked items which are against the rule they will see an error which will deny the links and the links will not be created.

Stopped by Link Rule Error Message
Error Message

Restrictions on use

Finally there are restrictions in how this option is accessed. For instance a Link Group cannot be used in conjunction with the Cardinality. Also the options to create or modify cross references must be checked or the Cardinality option will be disabled.

For information on getting started in Link Rules click here