org.datanucleus.store.rdbms.key

Class ForeignKey

java.lang.Object

org.datanucleus.store.rdbms.key.ForeignKey

public class ForeignKey
extends Object

Representation of a foreign key to another table.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ForeignKey.FKAction Enum representing an action on the FK.

Field Summary

Fields

Modifier and Type	Field and Description
protected List<Column>	columns Columns that the key relates to.
protected String	name Name of the key.
protected Table	table Table that the key applies to.

Constructor Summary

Constructors

Constructor and Description
ForeignKey(boolean initiallyDeferred) Constructor.
ForeignKey(JavaTypeMapping mapping, DatastoreAdapter dba, DatastoreClass refTable, boolean initiallyDeferred) Constructor.

Method Summary

Modifier and Type	Method and Description
void	addColumn(Column col) Class to add a column to the key
void	addColumn(Column col, Column refCol) Method to add a Column.
protected void	assertSameDatastoreObject(Column col) Utility to assert if the column is for a different table.
boolean	equals(Object obj) Equality operator.
String	getColumnList() Accessor for the column list
static String	getColumnList(Collection cols) Method to return the list of columns which the key applies to.
List<Column>	getColumns() Accessor for the columns that the key relates to.
String	getName() Accessor for the key name.
String	getRefColumnList()
DatastoreClass	getRefTable()
Table	getTable() Accessor for the table
int	hashCode() Hashcode operator.
boolean	isEqual(ForeignKey fk)
void	setColumn(int seq, Column col, Column refCol) Set the datastore field for the specified position seq
void	setDeleteAction(ForeignKey.FKAction deleteAction) Mutator for deleteAction.
void	setForMetaData(org.datanucleus.metadata.ForeignKeyMetaData fkmd) Convenience mutator for setting the specification based on MetaData
protected static void	setMinSize(List list, int size)
void	setName(String name) Mutator for the key name.
void	setUpdateAction(ForeignKey.FKAction updateAction) Mutator for updateAction.
boolean	startsWith(org.datanucleus.store.rdbms.key.Key key) Check if this starts with the same columns specified in key.
String	toString() Stringify method.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

name

protected String name

Name of the key.

table

protected Table table

Table that the key applies to.

columns

protected List<Column> columns

Columns that the key relates to.

Constructor Detail

ForeignKey

public ForeignKey(boolean initiallyDeferred)

Constructor.

Parameters:

initiallyDeferred - Whether the constraints are deferred

ForeignKey

public ForeignKey(JavaTypeMapping mapping,
                  DatastoreAdapter dba,
                  DatastoreClass refTable,
                  boolean initiallyDeferred)

Constructor.

Parameters:

mapping - The type mapping for this Foreign-key field

dba - Datastore adapter

refTable - Referred to table

initiallyDeferred - Whether they are deferred

Method Detail

setForMetaData

public void setForMetaData(org.datanucleus.metadata.ForeignKeyMetaData fkmd)

Convenience mutator for setting the specification based on MetaData

Parameters:

fkmd - ForeignKey MetaData definition

setDeleteAction

public void setDeleteAction(ForeignKey.FKAction deleteAction)

Mutator for deleteAction.

Parameters:

deleteAction - The deleteAction to set.

setUpdateAction

public void setUpdateAction(ForeignKey.FKAction updateAction)

Mutator for updateAction.

Parameters:

updateAction - The updateAction to set.

addColumn

public void addColumn(Column col,
                      Column refCol)

Method to add a Column.

Parameters:

col - The column to add

refCol - The column to reference

getRefTable

public DatastoreClass getRefTable()

getRefColumnList

public String getRefColumnList()

setColumn

public void setColumn(int seq,
                      Column col,
                      Column refCol)

Set the datastore field for the specified position seq

Parameters:

seq - the specified position

col - the datastore field

refCol - the foreign (refered) datastore field

hashCode

public int hashCode()

Hashcode operator.

Returns:

The hashcode

equals

public boolean equals(Object obj)

Equality operator.

Parameters:

obj - Object to compare against

Returns:

Whether they are equal.

isEqual

public boolean isEqual(ForeignKey fk)

toString

public String toString()

Stringify method. Generates the foreign key statement ready for use in an SQL call.

Overrides:

toString in class Object

Returns:

String version of this object.

getName

public String getName()

Accessor for the key name.

Returns:

Key name

getTable

public Table getTable()

Accessor for the table

Returns:

table

getColumns

public List<Column> getColumns()

Accessor for the columns that the key relates to.

Returns:

the List of columns.

getColumnList

public String getColumnList()

Accessor for the column list

Returns:

The column list

addColumn

public void addColumn(Column col)

Class to add a column to the key

Parameters:

col - The column to add

startsWith

public boolean startsWith(org.datanucleus.store.rdbms.key.Key key)

Check if this starts with the same columns specified in key.

Parameters:

key - the Key (may be multiple number of columns)

Returns:

true if this columns starts with columns specified in key

setName

public void setName(String name)

Mutator for the key name.

Parameters:

name - The key name

assertSameDatastoreObject

protected void assertSameDatastoreObject(Column col)

Utility to assert if the column is for a different table.

Parameters:

col - The column to compare with

setMinSize

protected static void setMinSize(List list,
                                 int size)

getColumnList

public static String getColumnList(Collection cols)

Method to return the list of columns which the key applies to.

Parameters:

cols - The columns.

Returns:

The column list.