Class PrefetchSelectQuery<T>

java.lang.Object

org.apache.cayenne.query.CacheableQuery

org.apache.cayenne.query.AbstractQuery

org.apache.cayenne.query.FluentSelect<T, ObjectSelect<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

See Also:

• Serialized Form

Field Summary

Fields

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

Fields inherited from class FluentSelect

dbEntityName, distinct, entityName, entityType, having, havingExpressionIsActive, metaData, orderings, where

Modifier and Type	Field	Description
protected String	dbEntityName
protected boolean	distinct
protected String	entityName
protected Class<?>	entityType
protected Expression	having
protected boolean	havingExpressionIsActive
protected org.apache.cayenne.query.ObjectSelectMetadata	metaData
protected Collection<Ordering>	orderings
protected Expression	where

Fields inherited from class AbstractQuery

root

Modifier and Type	Field	Description
protected Object	root	The root object this query.

Fields inherited from class CacheableQuery

logger

Modifier and Type	Field	Description
protected static final org.slf4j.Logger	logger

Constructor Summary

Constructors

Constructor	Description
PrefetchSelectQuery(CayennePath 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.
void	addResultPath(Expression 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.
CayennePath	getPrefetchPath()	Returns the prefetchPath.
Collection<ASTPath>	getResultPaths()	Returns extra result paths.
void	removeResultPath(String path)	Removes an extra result path.
void	removeResultPath(CayennePath 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	setPrefetchPath(CayennePath prefetchPath)	Sets the prefetchPath.
void	setPrefetchTree(PrefetchTreeNode prefetch)	Clean set of the prefetch tree without any merge with existing nodes.

Methods inherited from class ObjectSelect

aggregate, avg, column, columnQuery, columnQuery, columns, count, count, createMetadata, createQuery, dataRowQuery, dataRowQuery, dbQuery, dbQuery, distinct, fetchDataRows, getBaseMetaData, getMetaData, having, having, max, max, min, min, query, query, query, query, selectCount, selectFirst, sum

Modifier and Type	Method	Description
<E> ColumnSelect<E>	aggregate(BaseProperty<E> property, String function, Class<E> type)	Select result of some function, that aggregates values.
<E extends Number> ColumnSelect<E>	avg(NumericProperty<E> property)	Select average value of property
<E> ColumnSelect<E>	column(Property<E> property)	Select one specific property.
static ColumnSelect<Object[]>	columnQuery(Class<?> entityType, Property<?>... columns)	Creates a ColumnSelect that will fetch multiple columns of a given ObjEntity
static <E> ColumnSelect<E>	columnQuery(Class<?> entityType, Property<E> column)	Creates a ColumnSelect that will fetch single property that can be resolved against a given ObjEntity class.
ColumnSelect<Object[]>	columns(Property<?>... properties)	Select only specific properties.
ColumnSelect<Long>	count()	Select COUNT(*)
ColumnSelect<Long>	count(BaseProperty<?> property)	Select COUNT(property)
protected org.apache.cayenne.query.ObjectSelectMetadata	createMetadata()
Query	createQuery(Map<String,?> parameters)	This method is intended for internal use in a MappedSelect.
static ObjectSelect<DataRow>	dataRowQuery(Class<?> entityType)	Creates a ObjectSelect that fetches data for an ObjEntity determined from a provided class.
static ObjectSelect<DataRow>	dataRowQuery(Class<?> entityType, Expression expression)	Creates a ObjectSelect that fetches data for an ObjEntity determined from a provided class and uses provided expression for its qualifier.
static ObjectSelect<DataRow>	dbQuery(String dbEntityName)	Creates a ObjectSelect that fetches DataRows for a DbEntity determined from provided "dbEntityName".
static ObjectSelect<DataRow>	dbQuery(String dbEntityName, Expression expression)	Creates a ObjectSelect that fetches DataRows for a DbEntity determined from provided "dbEntityName" and uses provided expression for its qualifier.
ObjectSelect<T>	distinct()
ObjectSelect<DataRow>	fetchDataRows()	Forces query to fetch DataRows.
protected org.apache.cayenne.query.ObjectSelectMetadata	getBaseMetaData()
QueryMetadata	getMetaData(EntityResolver resolver)	Returns default select parameters.
ObjectSelect<T>	having(String expressionString, Object... parameters)	Appends a having qualifier expression of this query, using provided expression String and an array of position parameters.
ObjectSelect<T>	having(Expression expression)	Appends a having qualifier expression of this query.
<E> ColumnSelect<E>	max(ComparableProperty<E> property)	Select maximum value of property
<E extends Number> ColumnSelect<E>	max(NumericProperty<E> property)	Select maximum value of property
<E> ColumnSelect<E>	min(ComparableProperty<E> property)	Select minimum value of property
<E extends Number> ColumnSelect<E>	min(NumericProperty<E> property)	Select minimum value of property
static <T> ObjectSelect<T>	query(Class<T> entityType)	Creates a ObjectSelect that selects objects of a given persistent class.
static <T> ObjectSelect<T>	query(Class<T> resultType, String entityName)	Creates a ObjectSelect that fetches data for ObjEntity determined from provided "entityName", but fetches the result of a provided type.
static <T> ObjectSelect<T>	query(Class<T> entityType, Expression expression)	Creates a ObjectSelect that selects objects of a given persistent class and uses provided expression for its qualifier.
static <T> ObjectSelect<T>	query(Class<T> entityType, Expression expression, List<Ordering> orderings)	Creates a ObjectSelect that selects objects of a given persistent class and uses provided expression for its qualifier.
long	selectCount(ObjectContext context)	Quick way to select count of records
T	selectFirst(ObjectContext context)	Selects a single object using provided context.
<E extends Number> ColumnSelect<E>	sum(NumericProperty<E> property)	Select sum of values

Methods inherited from class FluentSelect

and, and, batchIterator, cacheGroup, cacheStrategy, cacheStrategy, castSelf, createSQLAction, dbEntityName, entityName, entityType, getActiveExpression, getColumns, getDbEntityName, getEntityName, getEntityType, getHaving, getLimit, getOffset, getOrderings, getPageSize, getPrefetches, getQueryTimeout, getStatementFetchSize, getWhere, initWithProperties, isDistinct, isFetchingDataRows, iterate, iterator, joinExpression, limit, localCache, localCache, offset, or, or, orderBy, orderBy, orderBy, orderBy, pageSize, prefetch, prefetch, queryTimeout, resolveRoot, route, select, selectOne, setActiveExpression, sharedCache, sharedCache, statementFetchSize, where, where

Modifier and Type	Method	Description
ObjectSelect<T>	and(Collection<Expression> expressions)	AND's provided expressions to the existing WHERE clause expression.
ObjectSelect<T>	and(Expression... expressions)	AND's provided expressions to the existing WHERE clause expression.
ResultBatchIterator<T>	batchIterator(ObjectContext context, int size)	Creates a ResultBatchIterator based on the provided context and batch size.
ObjectSelect<T>	cacheGroup(String cacheGroup)
ObjectSelect<T>	cacheStrategy(QueryCacheStrategy strategy)
ObjectSelect<T>	cacheStrategy(QueryCacheStrategy strategy, String cacheGroup)
protected <E> E	castSelf()	Utility method to perform (re)cast this type, doesn't perform any checks, so use with caution.
SQLAction	createSQLAction(SQLActionVisitor visitor)	A callback method invoked by Cayenne during the final execution phase of the query run.
ObjectSelect<T>	dbEntityName(String dbEntityName)	Sets the DbEntity name to fetch without changing the return type of the query.
ObjectSelect<T>	entityName(String entityName)	Sets the ObjEntity name to fetch without changing the return type of the query.
ObjectSelect<T>	entityType(Class<?> entityType)	Sets the type of the entity to fetch without changing the return type of the query.
protected Expression	getActiveExpression()
Collection<Property<?>>	getColumns()
String	getDbEntityName()
String	getEntityName()
Class<?>	getEntityType()
Expression	getHaving()	Returns a HAVING clause Expression of this query.
int	getLimit()
int	getOffset()
Collection<Ordering>	getOrderings()
int	getPageSize()
PrefetchTreeNode	getPrefetches()
int	getQueryTimeout()
int	getStatementFetchSize()
Expression	getWhere()	Returns a WHERE clause Expression of this query.
void	initWithProperties(Map<String,String> properties)
boolean	isDistinct()
boolean	isFetchingDataRows()
void	iterate(ObjectContext context, ResultIteratorCallback<T> callback)	Creates a ResultIterator based on the provided context and passes it to a callback for processing.
ResultIterator<T>	iterator(ObjectContext context)	Creates a ResultIterator based on the provided context.
protected ObjectSelect<T>	joinExpression(Collection<Expression> expressions, Function<Collection<Expression>, Expression> joiner)
ObjectSelect<T>	limit(int fetchLimit)	Resets query fetch limit - a parameter that defines max number of objects that should be ever be fetched from the database.
ObjectSelect<T>	localCache()	Instructs Cayenne to look for query results in the "local" cache when running the query.
ObjectSelect<T>	localCache(String cacheGroup)	Instructs Cayenne to look for query results in the "local" cache when running the query.
ObjectSelect<T>	offset(int fetchOffset)	Resets query fetch offset - a parameter that defines how many objects should be skipped when reading data from the database.
ObjectSelect<T>	or(Collection<Expression> expressions)	OR's provided expressions to the existing WHERE clause expression.
ObjectSelect<T>	or(Expression... expressions)	OR's provided expressions to the existing WHERE clause expression.
ObjectSelect<T>	orderBy(String property)	Add an ascending ordering on the given property.
ObjectSelect<T>	orderBy(String property, SortOrder sortOrder)	Add an ordering on the given property.
ObjectSelect<T>	orderBy(Collection<Ordering> orderings)	Adds a list of orderings to this query.
ObjectSelect<T>	orderBy(Ordering... orderings)	Add one or more orderings to this query.
ObjectSelect<T>	pageSize(int pageSize)	Resets query page size.
ObjectSelect<T>	prefetch(String path, int semantics)	Merges a prefetch path with specified semantics into the query prefetch tree.
ObjectSelect<T>	prefetch(PrefetchTreeNode prefetch)	Merges prefetch into the query prefetch tree.
ObjectSelect<T>	queryTimeout(int timeout)	Sets query timeout of PreparedStatement generated for this query.
protected Object	resolveRoot(EntityResolver resolver)
void	route(QueryRouter router, EntityResolver resolver, Query substitutedQuery)	Implements default routing mechanism relying on the EntityResolver to find DataMap based on the query root.
List<T>	select(ObjectContext context)	Selects objects using provided context.
T	selectOne(ObjectContext context)	Selects a single object using provided context.
protected void	setActiveExpression(Expression exp)
ObjectSelect<T>	sharedCache()	Instructs Cayenne to look for query results in the "shared" cache when running the query.
ObjectSelect<T>	sharedCache(String cacheGroup)	Instructs Cayenne to look for query results in the "shared" cache when running the query.
ObjectSelect<T>	statementFetchSize(int size)	Sets fetch size of the PreparedStatement generated for this query.
ObjectSelect<T>	where(String expressionString, Object... parameters)	Appends a qualifier expression of this query, using provided expression String and an array of position parameters.
ObjectSelect<T>	where(Expression expression)	Appends a qualifier expression of this query.

Methods inherited from class AbstractQuery

getRoot, setRoot, toString

Modifier and Type	Method	Description
Object	getRoot()	Returns the root of this query.
void	setRoot(Object value)	Sets the root of the query
String	toString()

Methods inherited from class CacheableQuery

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

Modifier and Type	Method	Description
String	getCacheGroup()
QueryCacheStrategy	getCacheStrategy()
void	setCacheGroup(String cacheGroup)
void	setCacheStrategy(QueryCacheStrategy strategy)
void	useLocalCache()	Instructs Cayenne to look for query results in the "local" cache when running the query.
void	useLocalCache(String cacheGroup)	Instructs Cayenne to look for query results in the "local" cache when running the query.
void	useSharedCache()	Instructs Cayenne to look for query results in the "shared" cache when running the query.
void	useSharedCache(String cacheGroup)	Instructs Cayenne to look for query results in the "shared" cache when running the query.

Methods inherited from class Object

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

Field Details

prefetchPath

protected CayennePath 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<ASTPath> resultPaths

Constructor Details

PrefetchSelectQuery

public PrefetchSelectQuery(CayennePath 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, ObjectSelect<T>>

getPrefetchPath

public CayennePath getPrefetchPath()

Returns the prefetchPath.

Since:

5.0 returns CayennePath instead of a plain String

setPrefetchPath

public void setPrefetchPath(String prefetchPath)

Sets the prefetchPath.

Parameters:

prefetchPath - The prefetchPath to set

See Also:

• setPrefetchPath(CayennePath)

setPrefetchPath

public void setPrefetchPath(CayennePath prefetchPath)

Sets the prefetchPath.

Parameters:

prefetchPath - The prefetchPath to set

Since:

5.0

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

addResultPath

public void addResultPath(Expression path)

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

Parameters:

path - a path expression

Since:

5.0

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.

See Also:

• removeResultPath(CayennePath)

removeResultPath

public void removeResultPath(CayennePath 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.

Since:

5.0

getResultPaths

public Collection<ASTPath> getResultPaths()

Returns extra result paths.

Since:

1.2, 5.0 returns collection of CayennePath