Single-cardinality relationships that store the relationship in the child

Some applications store a single child entity so that the relationship is stored in the child rather than in the parent. In other words, the child contains a foreign key whose value is identical to the value stored in the parent's primary key.

Figure 4 illustrates this special type of single-cardinality relationship.

Figure 4. Single-cardinality business object with relationship stored in the child


Applications use this type of single-cardinality relationship when child data does not exist independently of its parent and can be accessed only through its parent. Such child data is never owned by more than one parent, and requires that the parent and its primary-key value exist before the child and its foreign-key value can be created.

To accommodate such applications, the connector also supports hierarchical business objects that contain a child with single cardinality but store the relationship in the child rather than in the parent.

To specify that a parent business object contains a single-cardinality child in this special way, when you specify the application-specific information of the attribute that contains the child, do not include the CONTAINMENT parameter. For more information, see Attributes that represent a single-cardinality child business object.

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