LEARN. PRACTICE. GROW.Concept and mechanism
A relationship represents cardinality, identity, and dependency between entities. If a change affects several services and each service participates in several changes, the link may need its own object with specific criticality or evidence. The junction-object pattern with two master-detail relationships supports many-to-many, but does not automatically solve independent retention. Deletion and access still depend on chosen relationships. For an association with two masters, review access to both and the Sharing Settings; creating one relationship first does not remove the second’s influence. Choosing a model merely because a related list is convenient leaves important decisions implicit.
Guided application
Converting lookup to master-detail requires examining existing children, including parentless records. Converting the other way involves addressing dependent roll-up summaries and configuring independent child security. Neither change is merely relabeling or making a field required on a layout. Existing report types and reports may stop working after conversion even when data remains present. Prepare a dependency inventory, tests for creation, deletion, access, and reporting, and a recovery decision. Where retention requires evidence preservation, consider deactivating old entities while validating the final model. Do not assign a fictitious parent merely to satisfy a technical conversion condition.
A change-service association stores acceptance evidence. If deleting a service also deletes the association, cardinality can be correct while retention is wrong. Test both requirements separately before approving master-detail.
Common pitfalls
Many-to-many treated as guaranteed retention; conversion without a roll-up inventory; an unavailable report automatically interpreted as data loss.
Related topics: Requirements, access, and platform extensions · Fields, migrations, and external data · Formulas, validations, and aggregates
A relationship must meet cardinality, access, retention, and reporting needs. Conversion is a functional change with dependencies.
Reference: Effects of Converting Master-Detail to Lookup · Platform App Builder guide SU 26