Chapter 9 Working with Data Models
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. |
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