This interface provides an abstraction for the original relational database
information used to generate an Entity container managed persistence bean.
Changes to cmp or cmr fields made after generation will not be reflected in
this interface and may invalidation the original mappings. Thus, this
information is intended to serve only as a hint for application server
cmpFieldName - to use for locating column mapping.
name of column which represents the cmp field in #getTable() or
null if this cmp field does not have a mapping (this could happen because
of a change to the set of cmp fields or changes to the specific cmp field).
Obtain the foreign key columns used to express a 1:N relationship. This
method will return the mapping only from the dependant EJB. Consider a
an Order to LineItem relationship (Order contains many line items)
where Order has a cmr field called lineItems and LineItem has a cmr field
named order. Invoking getRelationshipColumn("lineItems") on
Order would return null; however, the same invocation on LineItem would
return the foreign keys which reference Order. Mapping information for
M:N relationships is obtain via the #getRelationshipTable(java.lang.String)
cmrFieldName - to use for locating column mapping.
name of columns representing the cmr field in #getTable() or null
if the field was not present during creation or is participating in a
many to many relationship.