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 and 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 and Description
Attribute	getAttribute() Gets the model's attribute.
Backend	getBackend() Gets the backend.
ColumnMetaData[]	getColumns() Gets the database's column meta data.
String	migrate() Migrates the column.

Methods inherited from class java.lang.Object

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

Constructor Detail

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 Detail

getBackend

public Backend getBackend()

Gets the backend.

Returns:

the backend

getAttribute

public Attribute getAttribute()

Gets the model's attribute.

Returns:

the model's attribute

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