(Optional) Points to the JoinTable, CollectionTable or AssociationOverride attribute which this JoinColumn belongs to. If this JoinColumn is not part of a JoinTable, CollectionTable or AssociationOverride, this field should stay empty. If this field is populated and references a JoinTable, this JoinColumn represents a foreign key column of the join table which reference the primary table of the entity owning the association. (I.e. the owning side of the association). If this field is populated and references a collection table, this JoinColumn references the primary table of the entity. The default only applies if a single join column is used. The default is the same as for JoinColumn (i.e., the concatenation of the following: the name of the entity; "_"; the name of the referenced primary key column.) However, if there is more than one join column, a JoinColumn annotation must be specified for each join column . In this case, both the name and the referencedColumnName elements must be specified in each such JoinColumn annotation. If this field is populated and references an AssociationOverride, this JoinColumn represents a join column being mapped to a persistent attribute. The joinColumn elements must be specified if a foreign key mapping is used in the overriding of the mapping of the relationship. The joinColumn element must not be specified if a join table is used in the overriding of the mapping of the relationship.

public string AttributeRef