Association Checks (CDM)

The following CDM model checks are made on associations:

Check

Description and Correction

Association name and code uniqueness

Association names and codes must be unique in the namespace.

Manual correction: Modify the duplicate name/code

Automatic correction: Appends a number to the duplicate name/code.

Number of links >= 2

An association is isolated and therefore does not define a relationship between entities.

Manual correction: Define at least two links between the isolated association and one or several entities.

Automatic correction: None.

Number of links = 2 with an identifier link

An identifier link introduces a dependency between two entities. An association with this type of link must be binary.

Manual correction: Delete the unnecessary links or clear the Identifier check box for a link.

Automatic correction: None.

Number of identifier links <= 1

An identifier link introduces a dependency between two entities. There can only be one identifier link between two entities otherwise a circular dependency is created.

Manual correction: Clear the Identifier check box for one of the links.

Automatic correction: None.

Absence of properties with identifier links

An association with an identifier link cannot have any properties.

Manual correction: Move the association properties into the dependent entity (the one linked to the association with an identifier link).

Automatic correction: None.

Bijective association between two entities

There are bijective associations between two entities when a two-way one to one association between the entities exist. This is equivalent to a merge of two entities.

Manual correction: Merge the entities or modify the cardinality links.

Automatic correction: None.

Maximal cardinality links

An association with more than two links can only have links with a maximum cardinality greater than one.

Manual correction: Change the maximum cardinality of such links to be greater than 1.

Automatic correction: None.

Reflexive identifier links

An identifier link introduces a dependency between two entities. An association with this type of link cannot therefore be reflexive.

Manual correction: Change the relationship between the entities or clear the Identifier check box for a link.

Automatic correction: None.

Name uniqueness constraint between many-to-many associations and entities

A many-to-many association and an entity cannot have the same name or code.

Manual correction: Change the name or code of the many-to-many association or the name or code of the entity. If you do not, PDM generation will rename the generated table.

Automatic correction: None.


Created October 7, 2009. Send feedback on this help topic to Sybase Technical Publications: pubs@sybase.com