Relationships between objects

Object relationships are similar to primary and foreign keys in a database. The relationship definition specifies cardinality (how many records of one object type can be related to another) and whether the relationship is required. When you create a relationship between objects, Platform automatically creates a lookup field in each object that provides access to related records. Platform also automatically creates a view for related objects that is added to the appropriate pages for both objects.

End users will need to view and, in some cases, create and edit related records. Depending on the cardinality of the relationship and the permissions granted, the lookup field gives users the ability to view, attach, create, and remove related records.

By default, lookup fields allow users to select one or more records of the related object by displaying a selector page in a pop-up window. You can change this behavior by allowing users to select records from a picklist or you can hide the selector. Hiding the selector is useful for objects that a user cannot edit or on pages where you do not want them editing related objects. Picklists are limited to showing 1,000 records to avoid display issues. Use grid controls or record lists for objects where you anticipate exceeding that limit.