org.apache.cayenne.query
Class PrefetchSelectQuery

java.lang.Object
  org.apache.cayenne.query.AbstractQuery
      org.apache.cayenne.query.QualifiedQuery
          org.apache.cayenne.query.SelectQuery
              org.apache.cayenne.query.PrefetchSelectQuery

All Implemented Interfaces:

java.io.Serializable, GenericSelectQuery, ParameterizedQuery, Query, XMLSerializable

public class PrefetchSelectQuery
extends SelectQuery

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

Author:

Craig Miskell, Andrei Adamchik

See Also:

Serialized Form

Field Summary

protected ObjRelationship	lastPrefetchHint Stores the last ObjRelationship in the prefetch path.
protected SelectQuery	parentQuery
protected java.lang.String	prefetchPath The relationship path from root objects to the objects being prefetched.
protected java.util.Collection	resultPaths

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

customDbAttributes, distinct, DISTINCT_DEFAULT, DISTINCT_PROPERTY, orderings, parentObjEntityName, parentQualifier

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

qualifier

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

name, root

Fields inherited from interface org.apache.cayenne.query.GenericSelectQuery

CACHE_POLICY_DEFAULT, CACHE_POLICY_PROPERTY, FETCH_LIMIT_DEFAULT, FETCH_LIMIT_PROPERTY, FETCHING_DATA_ROWS_DEFAULT, FETCHING_DATA_ROWS_PROPERTY, LOCAL_CACHE, NO_CACHE, PAGE_SIZE_DEFAULT, PAGE_SIZE_PROPERTY, REFRESHING_OBJECTS_DEFAULT, REFRESHING_OBJECTS_PROPERTY, RESOLVING_INHERITED_DEFAULT, RESOLVING_INHERITED_PROPERTY, SHARED_CACHE

Constructor Summary

PrefetchSelectQuery(EntityResolver resolver, SelectQuery parentQuery, java.lang.String prefetch)
Deprecated. since 1.2 - passing EntityResolver in constructor is no longer needed, as prefetch query configuration alogrithm is moved out of this class. In fact this constructor will not correctly configure query to handle flattened prefetches.

PrefetchSelectQuery(SelectQuery parentQuery, java.lang.String prefetchPath, ObjRelationship lastPrefetchHint)
Creates a new disjoint prefetch select query.

Method Summary

void	addResultPath(java.lang.String path) Configures an "extra" path that will resolve to an extra column (or columns) in the result set.
ObjRelationship	getLastPrefetchHint() Retunrs last incoming ObjRelationship in the prefetch relationship chain.
SelectQuery	getParentQuery()
java.lang.String	getPrefetchPath() Returns the prefetchPath.
java.util.Collection	getResultPaths() Returns extra result paths.
void	removeResultPath(java.lang.String path) Removes an extra result path.
void	setLastPrefetchHint(ObjRelationship relationship)
void	setParentQuery(SelectQuery parentQuery)
void	setPrefetchPath(java.lang.String prefetchPath) Sets the prefetchPath.

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

addCustomDbAttribute, addCustomDbAttributes, addOrdering, addOrdering, addOrdering, addOrderings, addPrefetch, addPrefetches, andParentQualifier, clearOrderings, clearPrefetches, createQuery, createSQLAction, encodeAsXML, getCachePolicy, getCustomDbAttributes, getFetchLimit, getMetaData, getOrderings, getPageSize, getParentObjEntityName, getParentQualifier, getPrefetches, getPrefetchTree, initWithProperties, isDistinct, isFetchingCustomAttributes, isFetchingDataRows, isQualifiedOnParent, isRefreshingObjects, isResolvingInherited, orParentQualifier, queryWithParameters, queryWithParameters, removeOrdering, removePrefetch, route, setCachePolicy, setDistinct, setFetchingDataRows, setFetchLimit, setPageSize, setParentObjEntityName, setParentQualifier, setPrefetchTree, setRefreshingObjects, setResolvingInherited

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

andQualifier, getQualifier, orQualifier, setQualifier

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

getName, getRoot, setName, setRoot, toString

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

getName, getRoot, setName, setRoot

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

getName, getRoot, setName, setRoot

Field Detail

parentQuery

protected SelectQuery parentQuery

prefetchPath

protected java.lang.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 java.util.Collection resultPaths

Constructor Detail

PrefetchSelectQuery

public PrefetchSelectQuery(EntityResolver resolver,
                           SelectQuery parentQuery,
                           java.lang.String prefetch)

Deprecated. since 1.2 - passing EntityResolver in constructor is no longer needed, as prefetch query configuration alogrithm is moved out of this class. In fact this constructor will not correctly configure query to handle flattened prefetches.

Creates a prefetch query based on parent query.

Since:

1.1

PrefetchSelectQuery

public PrefetchSelectQuery(SelectQuery parentQuery,
                           java.lang.String prefetchPath,
                           ObjRelationship lastPrefetchHint)

Creates a new disjoint prefetch select query.

Since:

1.2

Method Detail

getPrefetchPath

public java.lang.String getPrefetchPath()

Returns the prefetchPath.

Returns:

String

setPrefetchPath

public void setPrefetchPath(java.lang.String prefetchPath)

Sets the prefetchPath.

Parameters:

prefetchPath - The prefetchPath to set

getParentQuery

public SelectQuery getParentQuery()

Since:

1.1

setParentQuery

public void setParentQuery(SelectQuery parentQuery)

Since:

1.1

getLastPrefetchHint

public ObjRelationship getLastPrefetchHint()

Retunrs last incoming ObjRelationship in the prefetch relationship chain.

Since:

1.1

setLastPrefetchHint

public void setLastPrefetchHint(ObjRelationship relationship)

Since:

1.1

addResultPath

public void addResultPath(java.lang.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(java.lang.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 purspose of this method "db:ARTIST_NAME" and "obj:artistName" are not the same, though both will resolve to the same column name.

getResultPaths

public java.util.Collection getResultPaths()

Returns extra result paths.

Since:

1.2