Implementing a relationship

Once you have created a relationship definition within Relationship Designer Express, you are ready to implement the relationship within the map. For instructions on creating relationship definitions, see Creating relationship definitions.

To implement a relationship, you can use the relationship function blocks in the map's destination object or add Mapping API methods to the code of attributes in the map's destination object.

Table 89 shows the function blocks to use.

Table 89. Relationship function blocks

Kind of relationship Function block For more information
Lookup General/APIs/Relationship/Retrieve Instances
General/APIs/Relationship/Retrieve Participants
"Using lookup relationships"
Simple Identity General/APIs/Identity Relationship/Maintain Simple Identity Relationship
General/APIs/Identity Relationship/Maintain Child
Verb
"Using simple identity relationships"
Composite Identity General/APIs/Identity Relationship/Maintain
Composite Relationship
General/APIs/Identity Relationship/Maintain Child
Verb
General/APIs/Identity Relationship/Update My Children (optional)
"Using composite identity relationships"
Custom General/APIs/Relationship/Create Relationship
General/APIs/Identity Relationship/Add My Children
General/APIs/Relationship/Add Participant

Table 89 shows the Mapping API methods that maintain the different kinds of relationships.

Table 90. Mapping API methods for relationships

Kind of relationship Mapping API method For more information
Lookup retrieveInstances()retrieveParticipants() "Using lookup relationships"
Simple Identity maintainSimpleIdentityRelationship()
maintainChildVerb()
"Using simple identity relationships"
Composite Identity maintainCompositeRelationship()maintainChildVerb()
updateMyChildren() (optional)
"Using composite identity relationships"
Custom create()addMyChildren()addParticipant() "Maintaining custom relationships"

When transforming relationship attributes, a map needs to know the calling context of the map. To determine the calling context, the map needs the following information from the map execution context:

These two factors tell the map what actions need to be taken on the relationship tables.

For the relationships in Table 89, the associated Mapping API methods perform the appropriate operations on the relationship tables. Therefore, these methods require that the calling context and business object verb be passed in as arguments.

Copyright IBM Corp. 2004