It is used to join the primary table of an entity subclass in the JOINED mapping strategy to the primary table of its superclass; it is used within a SecondaryTable annotation to join a secondary table to a primary table; and it may be used in a OneToOne mapping in which the primary key of the referencing entity is used as a foreign key to the referenced entity.
If no PrimaryKeyJoinColumn annotation is specified for a subclass in the JOINED mapping strategy, the foreign key columns are assumed to have the same names as the primary key columns of the primary table of the superclass.
Examples
Example: Customer and ValuedCustomer subclass [Entity] [Table(name="CUST")] [Inheritance(strategy=JOINED)] [DiscriminatorValue("CUST")] public class Customer { ... } [Entity] [Table(name="VCUST")] [DiscriminatorValue("VCUST")] [PrimaryKeyJoinColumn(name="CUST_ID")] public class ValuedCustomer extends Customer { ... }
Assembly: NPersistence (in NPersistence.dll) Version: 2.0.0.0 (2.0.0.0)
Syntax
C# |
public sealed class PrimaryKeyJoinColumn : Attribute
Members
All Members | Constructors | Fields |
Public Protected | Instance Static | Declared Inherited | XNA Framework Only .NET Compact Framework Only |
Member | Description | |
---|---|---|
PrimaryKeyJoinColumn()()()() | Initializes a new instance of the PrimaryKeyJoinColumn class | |
ColumnDefinition | (Optional) The SQL fragment that is used when generating the
DDL for the column. This should not be specified for a
OneToOne primary key association.
Defaults to the generated SQL to create a column of the
inferred type.
| |
Name |
(Optional) The name of the primary key column of the current table.
Defaults to the same name as the primary key column
of the primary table of the superclass (JOINED mapping strategy); the same
name as the primary key column of the primary table
(SecondaryTable mapping); or the same name as the
primary key column for the table for the referencing entity
(OneToOne mapping).
| |
ReferencedColumnName |
(Optional) The name of the primary key column of the table
being joined to. Defaults to the same name as the primary
key column of the primary table of the superclass
(JOINED mapping strategy); the same name as the
primary key column of the primary table
(SecondaryTable mapping); or the same name as the
primary key column for the table for the referencing entity
(OneToOne mapping).
| |
tableRef |
(Optional) Only required when this PrimaryKeyJoinColumn belongs to a SecondaryTable annontaion.
If populated, this PrimaryKeyJoinColumn represetns a column that is used to join with
the primary table.
Defaults to the column(s) of the same name(s)
as the primary key column(s) in the primary table.
|
Inheritance Hierarchy
System..::..Attribute
NPersistence..::..PrimaryKeyJoinColumn