org.deegree.io.datastore.sql.transaction.delete
Class DeleteHandler

java.lang.Object
  org.deegree.io.datastore.sql.AbstractRequestHandler
      org.deegree.io.datastore.sql.transaction.delete.DeleteHandler

public class DeleteHandler
extends AbstractRequestHandler

Handler for Delete operations (which usually occur as parts of Transaction requests).

When a Delete operation is performed, the following actions are taken:

• the FeatureIds of all (root) feature instances that match the associated Filter are determined
• the FeatureGraph is built in order to determine which features may be deleted without removing subfeatures of independent features
• the TableGraph is built that contains explicit information on all table rows that have to be deleted (and their dependencies)
• the TableNodes of the TableGraph are sorted in topological order, i.e. they may be deleted in that order without violating any foreign key constraints

Version:

$Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18 Jun 2009) $

Author:

Markus Schneider, last edited by: $Author: mschneider $

See Also:

FeatureGraph, TableGraph

Field Summary

Fields inherited from class org.deegree.io.datastore.sql.AbstractRequestHandler

aliasGenerator, conn, datastore, FT_COLUMN, FT_PREFIX

Constructor Summary

DeleteHandler(SQLTransaction dsTa, TableAliasGenerator aliasGenerator, java.sql.Connection conn, java.lang.String lockId)
Creates a new DeleteHandler from the given parameters.

Method Summary

void	deleteOrphanedPropertyRows(TableRelation relation, java.lang.Object[] keyValues) Delete orphaned rows in the specified property table (target table of the given TableRelation).
(package private) TableNode	determineJTNode(FeatureId fid, FeatureId subFid, TableRelation relation1, TableRelation relation2) Determines the row in the join table that connects a certain feature with a subfeature.
(package private) java.util.List<TableNode>	determinePropNodes(FeatureId fid, TableRelation relation) Determines the TableNode that represent the simple/geometry properties in the property table attached by the given TableRelation.
int	performDelete(MappedFeatureType ft, Filter filter) Deletes the features from the Datastore that have a certain type and are matched by the given filter.

Methods inherited from class org.deegree.io.datastore.sql.AbstractRequestHandler

appendColumnsList, appendFeatureIdColumns, appendFeatureIdConstraint, appendFeatureIdConstraint, appendJoinCondition, appendJoins, appendQualifiedColumn, appendQualifiedColumnsList, determineAffectedAndModifiableFIDs, determineAffectedFIDs, determineSubFeatures, determineSuperFeatures, extractFeatureId, extractFeatureIds, extractFeatureIdsForceUnique

Methods inherited from class java.lang.Object

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

Constructor Detail

DeleteHandler

public DeleteHandler(SQLTransaction dsTa,
                     TableAliasGenerator aliasGenerator,
                     java.sql.Connection conn,
                     java.lang.String lockId)

Creates a new DeleteHandler from the given parameters.

Parameters:

dsTa -

aliasGenerator -

conn -

lockId - optional id of associated lock (may be null)

Method Detail

performDelete

public int performDelete(MappedFeatureType ft,
                         Filter filter)
                  throws DatastoreException

Deletes the features from the Datastore that have a certain type and are matched by the given filter.

Parameters:

ft - non-abstract feature type of the features to be deleted

filter - constraints the feature instances to be deleted

Returns:

number of deleted feature instances

Throws:

DatastoreException

determinePropNodes

java.util.List<TableNode> determinePropNodes(FeatureId fid,
                                             TableRelation relation)
                                       throws DatastoreException

Determines the TableNode that represent the simple/geometry properties in the property table attached by the given TableRelation.

Parameters:

fid - id of the feature that owns the properties

relation - describes how the property table is joined to the feature table

Returns:

the simple/geometry properties in the the related property table

Throws:

DatastoreException

determineJTNode

TableNode determineJTNode(FeatureId fid,
                          FeatureId subFid,
                          TableRelation relation1,
                          TableRelation relation2)
                    throws DatastoreException

Determines the row in the join table that connects a certain feature with a subfeature.

Parameters:

fid - id of the (super-) feature

subFid - id of the subfeature

relation1 - describes how the join table is attached

relation2 - describes how the subfeature table is joined

Returns:

join table row (as a TableNode)

Throws:

DatastoreException

deleteOrphanedPropertyRows

public void deleteOrphanedPropertyRows(TableRelation relation,
                                       java.lang.Object[] keyValues)
                                throws DatastoreException

Delete orphaned rows in the specified property table (target table of the given TableRelation).

Only used by the UpdateHandler.

Parameters:

relation -

keyValues -

Throws:

DatastoreException