Package org.hibernate.dialect.unique

Class CreateTableUniqueDelegate

java.lang.Object

org.hibernate.dialect.unique.AlterTableUniqueDelegate

org.hibernate.dialect.unique.CreateTableUniqueDelegate

All Implemented Interfaces:

UniqueDelegate

Direct Known Subclasses:

SkipNullableUniqueDelegate

public class CreateTableUniqueDelegate
extends AlterTableUniqueDelegate

A UniqueDelegate which includes the unique constraint in the create table statement, except when called during schema migration.

• For columns marked unique, this results in a unique column definition.
• For named unique keys, it results in constraint abc unique(a,b,c) after the column list in create table.
• For unique keys with no explicit name, it results in unique(x, y) after the column list.

Counterintuitively, this class extends AlterTableUniqueDelegate, since it falls back to using alter table for schema migration.

Field Summary

Fields inherited from class org.hibernate.dialect.unique.AlterTableUniqueDelegate

dialect

Constructor Summary

Constructors

Constructor	Description
CreateTableUniqueDelegate(Dialect dialect)

Method Summary

Modifier and Type	Method	Description
protected void	appendUniqueConstraint(StringBuilder fragment, UniqueKey uniqueKey)
String	getAlterTableToAddUniqueKeyCommand(UniqueKey uniqueKey, Metadata metadata, SqlStringGenerationContext context)	Get the alter table command used to create the given unique key constraint, or return the empty string if the constraint was already included in the create table statement by UniqueDelegate.getTableCreationUniqueConstraintsFragment(org.hibernate.mapping.Table, org.hibernate.boot.model.relational.SqlStringGenerationContext).
String	getAlterTableToDropUniqueKeyCommand(UniqueKey uniqueKey, Metadata metadata, SqlStringGenerationContext context)	Get the alter table command used to drop the given unique key which was previously created by UniqueDelegate.getAlterTableToAddUniqueKeyCommand(org.hibernate.mapping.UniqueKey, org.hibernate.boot.Metadata, org.hibernate.boot.model.relational.SqlStringGenerationContext).
String	getColumnDefinitionUniquenessFragment(Column column, SqlStringGenerationContext context)	Get the SQL fragment used to make the given column unique as part of its column definition, usually just " unique", or return an empty string if uniqueness does not belong in the column definition.
String	getTableCreationUniqueConstraintsFragment(Table table, SqlStringGenerationContext context)	Get the SQL fragment used to specify the unique constraints on the given table as part of the create table command, with a leading comma, usually something like:

Methods inherited from class org.hibernate.dialect.unique.AlterTableUniqueDelegate

uniqueConstraintSql

Methods inherited from class java.lang.Object

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

Constructor Details

CreateTableUniqueDelegate

public CreateTableUniqueDelegate(Dialect dialect)

Method Details

getColumnDefinitionUniquenessFragment

public String getColumnDefinitionUniquenessFragment(Column column,
 SqlStringGenerationContext context)

Description copied from interface: UniqueDelegate

Get the SQL fragment used to make the given column unique as part of its column definition, usually just " unique", or return an empty string if uniqueness does not belong in the column definition.

This is for handling single columns explicitly marked unique, not for dealing with unique keys.

Specified by:

getColumnDefinitionUniquenessFragment in interface UniqueDelegate

Overrides:

getColumnDefinitionUniquenessFragment in class AlterTableUniqueDelegate

Parameters:

column - The column to which to apply the unique

context - A context for SQL string generation

Returns:

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

getTableCreationUniqueConstraintsFragment

public String getTableCreationUniqueConstraintsFragment(Table table,
 SqlStringGenerationContext context)

Description copied from interface: UniqueDelegate

Get the SQL fragment used to specify the unique constraints on the given table as part of the create table command, with a leading comma, usually something like:

, unique(x,y), constraint abc unique(a,b,c)

or return an empty string if there are no unique constraints or if the unique constraints do not belong in the table definition.

The implementation should iterate over the unique keys of the given table by calling Table.getUniqueKeys() and generate a fragment which includes all the unique key declarations.

Specified by:

getTableCreationUniqueConstraintsFragment in interface UniqueDelegate

Overrides:

getTableCreationUniqueConstraintsFragment in class AlterTableUniqueDelegate

Parameters:

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

context - A context for SQL string generation

Returns:

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

appendUniqueConstraint

protected void appendUniqueConstraint(StringBuilder fragment,
 UniqueKey uniqueKey)

getAlterTableToAddUniqueKeyCommand

public String getAlterTableToAddUniqueKeyCommand(UniqueKey uniqueKey,
 Metadata metadata,
 SqlStringGenerationContext context)

Description copied from interface: UniqueDelegate

Get the alter table command used to create the given unique key constraint, or return the empty string if the constraint was already included in the create table statement by UniqueDelegate.getTableCreationUniqueConstraintsFragment(org.hibernate.mapping.Table, org.hibernate.boot.model.relational.SqlStringGenerationContext).

Specified by:

getAlterTableToAddUniqueKeyCommand in interface UniqueDelegate

Overrides:

getAlterTableToAddUniqueKeyCommand in class AlterTableUniqueDelegate

Parameters:

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

metadata - Access to the bootstrap mapping information

context - A context for SQL string generation

Returns:

The alter table command

getAlterTableToDropUniqueKeyCommand

public String getAlterTableToDropUniqueKeyCommand(UniqueKey uniqueKey,
 Metadata metadata,
 SqlStringGenerationContext context)

Description copied from interface: UniqueDelegate

Get the alter table command used to drop the given unique key which was previously created by UniqueDelegate.getAlterTableToAddUniqueKeyCommand(org.hibernate.mapping.UniqueKey, org.hibernate.boot.Metadata, org.hibernate.boot.model.relational.SqlStringGenerationContext).

Specified by:

getAlterTableToDropUniqueKeyCommand in interface UniqueDelegate

Overrides:

getAlterTableToDropUniqueKeyCommand in class AlterTableUniqueDelegate

Parameters:

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

metadata - Access to the bootstrap mapping information

context - A context for SQL string generation

Returns:

The alter table command