Module org.tentackle.model

Package org.tentackle.model.migrate

Class ColumnMigrator

java.lang.Object

org.tentackle.model.migrate.ColumnMigrator

public class ColumnMigrator
extends Object

Handles the migration of columns.

Author:

harald

Constructor Summary

Constructors

Constructor	Description
ColumnMigrator(Entity entity, Attribute attribute, Backend backend, Collection<ColumnMetaData> columns)	Creates a column migrator.
ColumnMigrator(Entity entity, Attribute attribute, Backend backend, ColumnMetaData... columns)	Creates a column migrator.

Method Summary

Modifier and Type	Method	Description
Attribute	getAttribute()	Gets the model's attribute.
Backend	getBackend()	Gets the backend.
ColumnMetaData[]	getColumns()	Gets the database's column meta data.
Entity	getEntity()	Gets the migrated entity.
String	migrate()	Migrates the column.

Methods inherited from class java.lang.Object

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

Constructor Details

ColumnMigrator

public ColumnMigrator(Entity entity,
 Attribute attribute,
 Backend backend,
 ColumnMetaData... columns)

Creates a column migrator.

Parameters:

entity - the migrated entity

attribute - the model's attribute, null if drop columns

backend - the backend

columns - the database's column(s), null if add attribute

ColumnMigrator

public ColumnMigrator(Entity entity,
 Attribute attribute,
 Backend backend,
 Collection<ColumnMetaData> columns)

Creates a column migrator.

Parameters:

entity - the migrated entity

attribute - the model's attribute, null if drop columns

backend - the backend

columns - the database's column(s), null or empty if add attribute

Method Details

getBackend

public Backend getBackend()

Gets the backend.

Returns:

the backend

getEntity

public Entity getEntity()

Gets the migrated entity.

Returns:

the entity

getAttribute

public Attribute getAttribute()

Gets the model's attribute.

Returns:

the model's attribute, null if drop columns

getColumns

public ColumnMetaData[] getColumns()

Gets the database's column meta data.

Returns:

the database's column(s)

migrate

public String migrate()
               throws ModelException

Migrates the column.

Returns:

the SQL code, empty string if nothing to migrate

Throws:

ModelException - if migration failed