org.datanucleus.store.rdbms.key
Class CandidateKey

java.lang.Object
  org.datanucleus.store.rdbms.key.CandidateKey

Direct Known Subclasses:

PrimaryKey

public class CandidateKey
extends Object

Representation of a Candidate key. This represents a UNIQUE key on a column or columns.

Field Summary

protected List<org.datanucleus.store.mapped.DatastoreField>	columns Columns that the key relates to.
protected String	name Name of the key.
protected org.datanucleus.store.mapped.DatastoreContainerObject	table Table that the key applies to.

Constructor Summary

CandidateKey(org.datanucleus.store.mapped.DatastoreContainerObject table)
Constructor.

Method Summary

void	addDatastoreField(org.datanucleus.store.mapped.DatastoreField col) Class to add a column to the key
protected void	assertSameDatastoreObject(org.datanucleus.store.mapped.DatastoreField 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<org.datanucleus.store.mapped.DatastoreField>	getColumns() Accessor for the columns that the key relates to.
org.datanucleus.store.mapped.DatastoreContainerObject	getDatastoreContainerObject() Accessor for the table
String	getName() Accessor for the key name.
int	hashCode() Hashcode operator.
void	setDatastoreField(int seq, org.datanucleus.store.mapped.DatastoreField col) Mutator for the column spec, to add/change a column.
protected static void	setMinSize(List list, int size)
void	setName(String name) Mutator for the key name.
int	size() Accessor for the size.
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 org.datanucleus.store.mapped.DatastoreContainerObject table

Table that the key applies to.

columns

protected List<org.datanucleus.store.mapped.DatastoreField> columns

Columns that the key relates to.

Constructor Detail

CandidateKey

public CandidateKey(org.datanucleus.store.mapped.DatastoreContainerObject table)

Constructor.

Parameters:

table - Table to apply this key to

Method Detail

setDatastoreField

public void setDatastoreField(int seq,
                              org.datanucleus.store.mapped.DatastoreField col)

Mutator for the column spec, to add/change a column.

Parameters:

seq - Sequence number of the column

col - The column

size

public int size()

Accessor for the size.

Returns:

The size.

equals

public boolean equals(Object obj)

Equality operator.

Parameters:

obj - The object to compare against

Returns:

Whether the objects are equal

toString

public String toString()

Stringify method.

Overrides:

toString in class Object

Returns:

String version of this object.

getName

public String getName()

Accessor for the key name.

Returns:

Key name

getDatastoreContainerObject

public org.datanucleus.store.mapped.DatastoreContainerObject getDatastoreContainerObject()

Accessor for the table

Returns:

table

getColumns

public List<org.datanucleus.store.mapped.DatastoreField> 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

addDatastoreField

public void addDatastoreField(org.datanucleus.store.mapped.DatastoreField 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(org.datanucleus.store.mapped.DatastoreField col)

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

Parameters:

col - The column to compare with

hashCode

public int hashCode()

Hashcode operator.

Overrides:

hashCode in class Object

Returns:

The hashcode

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.