Package org.apache.cayenne.query

Class PrefetchSelectQuery<T>

java.lang.Object

org.apache.cayenne.query.CacheableQuery

org.apache.cayenne.query.AbstractQuery

org.apache.cayenne.query.FluentSelect<T>

org.apache.cayenne.query.ObjectSelect<T>

org.apache.cayenne.query.PrefetchSelectQuery<T>

All Implemented Interfaces:

Serializable, ParameterizedQuery, Query, Select<T>

public class PrefetchSelectQuery<T>
extends ObjectSelect<T>

A SelectQuery to perform a prefetch based on another query. Used internally by Cayenne and is normally never used directly.

Since:

4.2 this query extends ObjectSelect as part of the deprecation of the SelectQuery

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected ObjRelationship	lastPrefetchHint	Stores the last ObjRelationship in the prefetch path.
protected String	prefetchPath	The relationship path from root objects to the objects being prefetched.
protected Collection<String>	resultPaths

Fields inherited from class org.apache.cayenne.query.ObjectSelect

metaData

Fields inherited from class org.apache.cayenne.query.FluentSelect

dbEntityName, entityName, entityType, having, orderings, where

Fields inherited from class org.apache.cayenne.query.AbstractQuery

root

Fields inherited from class org.apache.cayenne.query.CacheableQuery

logger

Constructor Summary

Constructors

Constructor	Description
PrefetchSelectQuery(String prefetchPath, ObjRelationship lastPrefetchHint)	Creates a new disjoint prefetch select query.

Method Summary

Modifier and Type	Method	Description
void	addResultPath(String path)	Configures an "extra" path that will resolve to an extra column (or columns) in the result set.
ObjRelationship	getLastPrefetchHint()	Returns last incoming ObjRelationship in the prefetch relationship chain.
String	getPrefetchPath()	Returns the prefetchPath.
Collection<String>	getResultPaths()	Returns extra result paths.
void	removeResultPath(String path)	Removes an extra result path.
protected void	routePrefetches(QueryRouter router, EntityResolver resolver)
void	setLastPrefetchHint(ObjRelationship relationship)
void	setPrefetchPath(String prefetchPath)	Sets the prefetchPath.
void	setPrefetchTree(PrefetchTreeNode prefetch)	Clean set of the prefetch tree without any merge with existing nodes.

Methods inherited from class org.apache.cayenne.query.ObjectSelect

and, and, avg, avg, cacheGroup, cacheStrategy, cacheStrategy, column, columnQuery, columnQuery, columns, count, count, createQuery, dataRowQuery, dataRowQuery, dbEntityName, dbQuery, dbQuery, distinct, entityName, entityType, fetchDataRows, getBaseMetaData, getMetaData, having, having, isFetchingDataRows, limit, localCache, localCache, max, max, min, min, offset, or, or, orderBy, orderBy, orderBy, orderBy, pageSize, prefetch, prefetch, query, query, query, query, queryTimeout, selectCount, selectFirst, sharedCache, sharedCache, statementFetchSize, sum, sum, where, where

Methods inherited from class org.apache.cayenne.query.FluentSelect

batchIterator, createSQLAction, getColumns, getDbEntityName, getEntityName, getEntityType, getHaving, getLimit, getOffset, getOrderings, getPageSize, getPrefetches, getQueryTimeout, getStatementFetchSize, getWhere, initWithProperties, isDistinct, iterate, iterator, resolveRoot, route, select, selectOne

Methods inherited from class org.apache.cayenne.query.AbstractQuery

getRoot, setRoot, toString

Methods inherited from class org.apache.cayenne.query.CacheableQuery

getCacheGroup, getCacheStrategy, setCacheGroup, setCacheStrategy, useLocalCache, useLocalCache, useSharedCache, useSharedCache

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.cayenne.query.Query

createSQLAction, route

Field Details

prefetchPath

protected String prefetchPath

The relationship path from root objects to the objects being prefetched.

lastPrefetchHint

protected ObjRelationship lastPrefetchHint

Stores the last ObjRelationship in the prefetch path.

resultPaths

protected Collection<String> resultPaths

Constructor Details

PrefetchSelectQuery

public PrefetchSelectQuery(String prefetchPath,
 ObjRelationship lastPrefetchHint)

Creates a new disjoint prefetch select query.

Since:

3.1

Method Details

routePrefetches

protected void routePrefetches(QueryRouter router,
 EntityResolver resolver)

Overrides:

routePrefetches in class FluentSelect<T>

getPrefetchPath

public String getPrefetchPath()

Returns the prefetchPath.

setPrefetchPath

public void setPrefetchPath(String prefetchPath)

Sets the prefetchPath.

Parameters:

prefetchPath - The prefetchPath to set

setPrefetchTree

public void setPrefetchTree(PrefetchTreeNode prefetch)

Clean set of the prefetch tree without any merge with existing nodes.

Parameters:

prefetch - prefetch tree

Since:

4.2

getLastPrefetchHint

public ObjRelationship getLastPrefetchHint()

Returns last incoming ObjRelationship in the prefetch relationship chain.

Since:

1.1

setLastPrefetchHint

public void setLastPrefetchHint(ObjRelationship relationship)

Since:

1.1

addResultPath

public void addResultPath(String path)

Configures an "extra" path that will resolve to an extra column (or columns) in the result set.

Parameters:

path - A valid path expression. E.g. "abc" or "db:ABC" or "abc.xyz".

Since:

1.2

removeResultPath

public void removeResultPath(String path)

Removes an extra result path. Note that this method doesn't check for expression invariants, as it doesn't have a proper context to do so. E.g. for the purpose of this method "db:ARTIST_NAME" and "obj:artistName" are not the same, though both will resolve to the same column name.

getResultPaths

public Collection<String> getResultPaths()

Returns extra result paths.

Since:

1.2