Examples of com.sun.jdo.api.persistence.model.mapping.MappingTableElement

• com.sun.jdo.api.persistence.model.mapping.MappingTableElement
  This is an element which represents a database table. It exists (separately from TableElement in the database model) to allow the runtime to use a description of the underlying table that differs from the actual database. For example, mapping table contains a key which can be thought of as a "fake primary key" and designates the columns which the runtime will use to identify rows. It is analagous to the primary key of the underlying database table and is typically the same, however the important point is that it is not a requirement. The table in the database may have a different primary key or may have no primary key at all. Similarly, the mapping table contains a list of reference keys which can be thought of as "fake foreign key" objects and designate the column pairs used to join the primary table with a secondary table. These are analagous to foreign keys and may in fact contain identical pairs as the foreign key, but again, this is not a requirement. The foreign key may define a different set of pairs or may not exist at all. Although any set of pairs is legal, the user should be careful to define pairs which represent a logical relationship between the two tables. Any mapping table elements which are designated as primary tables have their key set up automatically. Any mapping table elements which are designated as secondary tables should not have their keys set up directly; the setup is automatically part of the pair definition which makes up the reference key. @author Mark Munro @author Rochelle Raccah @version %I%

Related Classes of com.sun.jdo.api.persistence.model.mapping.MappingTableElement