org.hibernate.dialect.unique

Class DefaultUniqueDelegate

java.lang.Object

org.hibernate.dialect.unique.DefaultUniqueDelegate

All Implemented Interfaces:

UniqueDelegate

Direct Known Subclasses:

DB2UniqueDelegate, InformixUniqueDelegate

public class DefaultUniqueDelegate
extends Object
implements UniqueDelegate

The default UniqueDelegate implementation for most dialects. Uses separate create/alter statements to apply uniqueness to a column.

Author:

Brett Meyer

Field Summary

Fields

Modifier and Type	Field and Description
protected Dialect	dialect

Constructor Summary

Constructors

Constructor and Description
DefaultUniqueDelegate(Dialect dialect) Constructs DefaultUniqueDelegate

Method Summary

Modifier and Type	Method and Description
String	getAlterTableToAddUniqueKeyCommand(UniqueKey uniqueKey, Metadata metadata) Get the SQL ALTER TABLE command to be used to create the given UniqueKey.
String	getAlterTableToDropUniqueKeyCommand(UniqueKey uniqueKey, Metadata metadata) Get the SQL ALTER TABLE command to be used to drop the given UniqueKey.
String	getColumnDefinitionUniquenessFragment(Column column) Get the fragment that can be used to make a column unique as part of its column definition.
String	getTableCreationUniqueConstraintsFragment(Table table) Get the fragment that can be used to apply unique constraints as part of table creation.
protected String	uniqueConstraintSql(UniqueKey uniqueKey)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

dialect

protected final Dialect dialect

Constructor Detail

DefaultUniqueDelegate

public DefaultUniqueDelegate(Dialect dialect)

Constructs DefaultUniqueDelegate

Parameters:

dialect - The dialect for which we are handling unique constraints

Method Detail

getColumnDefinitionUniquenessFragment

public String getColumnDefinitionUniquenessFragment(Column column)

Description copied from interface: UniqueDelegate

Get the fragment that can be used to make a column unique as part of its column definition.

This is intended for dialects which do not support unique constraints

Specified by:

getColumnDefinitionUniquenessFragment in interface UniqueDelegate

Parameters:

column - The column to which to apply the unique

Returns:

The fragment (usually "unique"), empty string indicates the uniqueness will be indicated using a different approach

getTableCreationUniqueConstraintsFragment

public String getTableCreationUniqueConstraintsFragment(Table table)

Description copied from interface: UniqueDelegate

Get the fragment that can be used to apply unique constraints as part of table creation. The implementation should iterate over the UniqueKey instances for the given table (see Table.getUniqueKeyIterator() and generate the whole fragment for all unique keys

Intended for Dialects which support unique constraint definitions, but just not in separate ALTER statements.

Specified by:

getTableCreationUniqueConstraintsFragment in interface UniqueDelegate

Parameters:

table - The table for which to generate the unique constraints fragment

Returns:

The fragment, typically in the form ", unique(col1, col2), unique( col20)". NOTE: The leading comma is important!

getAlterTableToAddUniqueKeyCommand

public String getAlterTableToAddUniqueKeyCommand(UniqueKey uniqueKey,
                                                 Metadata metadata)

Description copied from interface: UniqueDelegate

Get the SQL ALTER TABLE command to be used to create the given UniqueKey.

Specified by:

getAlterTableToAddUniqueKeyCommand in interface UniqueDelegate

Parameters:

uniqueKey - The UniqueKey instance. Contains all information about the columns

metadata - Access to the bootstrap mapping information

Returns:

The ALTER TABLE command

uniqueConstraintSql

protected String uniqueConstraintSql(UniqueKey uniqueKey)

getAlterTableToDropUniqueKeyCommand

public String getAlterTableToDropUniqueKeyCommand(UniqueKey uniqueKey,
                                                  Metadata metadata)

Description copied from interface: UniqueDelegate

Get the SQL ALTER TABLE command to be used to drop the given UniqueKey.

Specified by:

getAlterTableToDropUniqueKeyCommand in interface UniqueDelegate

Parameters:

uniqueKey - The UniqueKey instance. Contains all information about the columns

metadata - Access to the bootstrap mapping information

Returns:

The ALTER TABLE command