com.goldencode.p2j.persist

Class PresortCompoundQuery

java.lang.Object

com.goldencode.p2j.persist.AbstractQuery

com.goldencode.p2j.persist.DynamicQuery

com.goldencode.p2j.persist.CompoundQuery

com.goldencode.p2j.persist.PresortCompoundQuery

All Implemented Interfaces:

BufferCollection, RecordChangeListener, IndexInformation, P2JQuery, Presortable, PresortDelegate, QueryConstants, Scrollable, Openable

public final class PresortCompoundQuery
extends CompoundQuery
implements Presortable, PresortDelegate

PresortCompoundQuery is used when it is necessary to presort the results of a multi-table join, where the join cannot be performed at the database server. This is necessary when tables are being joined across databases, for example, though there may be other circumstances which could drive this requirement.

Upon the first request for a record, this query preselects all of its results in the order prescribed by each of its individual query components. It then sorts these results according to the sort criteria provided by one of the addSortCriterion() method variants. These results are cached. The appropriate record is returned for the original request, and thereafter, the cache is accessed for all subsequent record retrieval requests. The cache contains only primary key ID values; the actual records associated with these are retrieved on demand.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
private static class	PresortCompoundQuery.CursorResults An implementation of the Results interface which is backed by a dynamic Cursor object.

Nested classes/interfaces inherited from interface com.goldencode.p2j.persist.P2JQuery

P2JQuery.Parameter, P2JQuery.ParamResolver, P2JQuery.QueryEventListener, P2JQuery.QueryOpenedListener

Field Summary

Fields

Modifier and Type	Field and Description
private PresortCompoundQuery.CursorResults	cursorResults The cached results stored in the cursor, wrapped by Results interface.
private Presorter	sorter Helper which sorts preselected, unsorted results

Fields inherited from class com.goldencode.p2j.persist.CompoundQuery

currentRowDeleted, foundFirst, unregisterOnCleanup

Fields inherited from class com.goldencode.p2j.persist.DynamicQuery

cursor

Fields inherited from class com.goldencode.p2j.persist.AbstractQuery

closed, dynamicPredicate, errorHelper, excluded, included, indexedReposition, inverseSorting, lenientOffEnd, outer, parameterFilter

Fields inherited from interface com.goldencode.p2j.persist.QueryConstants

CURRENT, FIRST, ITERATE, LAST, NEXT, NONE, PREVIOUS, RETRIEVE_MODES, UNIQUE

Constructor Summary

Constructors

Constructor and Description
PresortCompoundQuery() Default constructor.

Method Summary

Modifier and Type	Method and Description
void	addComponent(Joinable query, int iteration, boolean outer) Add a joinable query to the compound query, and specify the nature of the iteration which will be performed (first, last, next, etc.) on that component, when the compound query is iterated.
void	addDynamicSortCriterion(Resolvable sort, boolean ascending) Add a single dynamic sort criterion, in the form of a Resolvable object which is resolved at runtime.
void	addSortCriterion(Resolvable sort) Add a single sort criterion, in the form of a Resolvable object which is resolved at sort time.
void	addSortCriterion(Resolvable sort, boolean descending) Add a single sort criterion, in the form of a Resolvable object which is resolved at runtime.
void	clearDynamicSortCriteria() Clears all sort criteria added dynamically.
void	clearResults() Clear the current results from the query, so the same query instance can be executed again, without having to re-open it.
protected PresortCompoundQuery.CursorResults	cursorAsResults() Get the cached results stored in the cursor, wrapped by Results interface.
void	enableBreakGroups() Enable all sort criteria set for this query to act as break group categories.
RecordBuffer[]	getRecordBuffers() Access the record buffers manipulated by this query, in order from left-most (outermost) table of the query's join (if any) to right-most (innermost) table.
Results	getSortedResults() Access the current, sorted results for this query.
PresortCompoundQuery	initialize() Initialization logic.
PresortCompoundQuery	initialize(boolean resolveOnce, boolean preselect) Initialization logic.
PresortCompoundQuery	initialize2f() Initialization logic.
logical	isFirst() Determine whether the query result row currently being visited is the first row in the presorted results list.
logical	isFirstOfGroup(int level) Determine whether the query result row currently being visited is the first row of the query's result set or the first row within a break group whose category is identified by the specified BREAK-BY level.
logical	isFirstOfGroup(integer level) Determine whether the query result row currently being visited is the first row of the query's result set or the first row within a break group whose category is identified by the specified BREAK-BY level.
logical	isFirstOfGroup(Resolvable key) Determine whether the query result row currently being visited is the first row within a break group whose category is identified by the specified resolvable object.
logical	isLast() Determine whether the query result row currently being visited is the last row in the presorted results list.
protected boolean	isLastOfBreakGroup(Resolvable key) Determine whether the query result row currently being visited is the last row within a break group whose category is identified by the specified resolvable object.
logical	isLastOfGroup(int level) Determine whether the query result row currently being visited is the last row of the query's result set or the last row within a break group whose category is identified by the specified BREAK-BY level.
logical	isLastOfGroup(integer level) Determine whether the query result row currently being visited is the last row of the query's result set or the last row within a break group whose category is identified by the specified BREAK-BY level.
logical	isLastOfGroup(Resolvable key) Determine whether the query result row currently being visited is the last row within a break group whose category is identified by the specified resolvable object.
protected boolean	isNewBreakGroup(Resolvable key) Determine whether the query result row currently being visited is the first row within a break group whose category is identified by the specified resolvable object.
boolean	isPresort() Indicate whether the query is of presort type.
protected boolean	isPresorted() Determines if the query is presorted, i.e.
boolean	next(boolean iterating, LockType lockType) Retrieve the next virtual, composite row of results for the compound query, overriding the lock type to apply to each underlying query.
protected void	presort() Presort the results stored in the cursor.

Methods inherited from class com.goldencode.p2j.persist.CompoundQuery

addComponent, addComponent, addCompoundComponent, addDynamicFilter, addExternalBuffers, afterReposition, canOptimize, cleanup, clearDynamicFilters, close, close, createResultListEntry, current, current, deleteResultListEntry, first, first, first, first, getBreakValue, getCombinedExecutionTime, getCombinedFqls, getOffEnd, getOffEndListeners, getOriginalComponents, getTableCount, hintFullResults, indexInformation, initReferenceRowSupport, iterate, last, last, last, last, loadByValues, loadRowAtCursor, next, next, next, notifyRepositionListeners, open, peekFirst, peekLast, peekNext, peekPrevious, postponeAccumulation, preselectResults, previous, previous, previous, previous, recordBuffers, registerCleaner, releaseAllBuffers, releaseBuffers, restoreAccumulation, retrieve, retrieve, setBrowsed, setDataRelation, setScrolling, setSkipDeletedRecord, setStandalone, stateChanged

Methods inherited from class com.goldencode.p2j.persist.DynamicQuery

_isOffEnd, backward, backward, currentRow, currentRowImpl, forward, forward, incrementMoves, isNativelyPreselect, isPreselect, isScrolling, reposition, reposition, repositionByID, repositionByID, repositionByID, reset, resetScrolling, size, verifyScrolling

Methods inherited from class com.goldencode.p2j.persist.AbstractQuery

_getNext, _isSkipDeletedRecord, accumulate, addAccumulator, addAccumulator, addBuffer, addBuffer, addQueryEventListener, addRepositionListener, afterReposition, afterReposition, bufferHandle, bufferHandle, bufferHandle, bufferHandle, bufferHandle, buffersMatch, changeForwardOnly, changeForwardOnly, deleteResultListEntry, exclude, forwardOnly, getCache, getCurrent, getCurrent, getCurrent, getCurrent, getCurrent, getCurrent, getCurrent, getCurrent, getDataRelation, getDefaultLock, getErrorHelper, getExternalBuffers, getExternalBuffersDefs, getFirst, getFirst, getFirst, getFirst, getFirst, getFirst, getFirst, getFirst, getLast, getLast, getLast, getLast, getLast, getLast, getLast, getLast, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getNumResults, getPrevious, getPrevious, getPrevious, getPrevious, getPrevious, getPrevious, getPrevious, getPrevious, getReferencedBuffers, hasAccumulators, hasAny, hasAny, hasAny, hasAny, hasOne, hasOne, hasOne, hasOne, include, indexInformation, indexInformation, isBrowsed, isDynamicPredicate, isErrorIfNull, isFatalError, isFetchOnReposition, isFillingBrowseRows, isIndexedReposition, isIterating, isLenientOffEnd, isOffEnd, isOmitAlias, isOpen, isRepositionNotificationActive, isSkipDeletedRecord, isStandalone, notifyQueryCloseListeners, notifyQueryOpenListeners, numBuffers, numResults, numResults, prepare, prepare, prepareFetch, prepareString, preprocessSubstitutionArguments, queryBackward, queryBackward, queryClose, queryForward, queryForward, queryOpen, queryReposition, queryReposition, queryRepositionByID, removeRepositionListener, setBuffers, setBuffers, setCache, setCache, setDynamicPredicate, setErrorIfNull, setFatalError, setFetchOnReposition, setFillingBrowseRows, setIndexedReposition, setIterating, setLenientOffEnd, setOmitAlias, setOuter, setParameterFilter, setPresort, silentCurrent, silentCurrent, silentFirst, silentFirst, silentLast, silentLast, silentNext, silentNext, silentPrevious, silentPrevious, silentUnique, silentUnique, translateSort, translateSort, translateWhere

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.goldencode.p2j.persist.P2JQuery

_getNext, addAccumulator, addAccumulator, addQueryEventListener, addRepositionListener, changeForwardOnly, changeForwardOnly, deleteResultListEntry, exclude, forwardOnly, getBasicLogging, getCache, getCurrent, getCurrent, getCurrent, getCurrent, getCurrent, getCurrent, getCurrent, getCurrent, getDataRelation, getFirst, getFirst, getFirst, getFirst, getFirst, getFirst, getFirst, getFirst, getJoin, getLast, getLast, getLast, getLast, getLast, getLast, getLast, getLast, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getNext, getNumResults, getPrevious, getPrevious, getPrevious, getPrevious, getPrevious, getPrevious, getPrevious, getPrevious, hasAny, hasAny, hasAny, hasAny, hasOne, hasOne, hasOne, hasOne, include, indexInformation, indexInformation, isBrowsed, isDynamicPredicate, isFetchOnReposition, isFillingBrowseRows, isFindByRowid, isIndexedReposition, isIterating, isOffEnd, isSkipDeletedRecord, isStandalone, notifyQueryCloseListeners, notifyQueryOpenListeners, prepare, prepare, prepareString, queryBackward, queryBackward, queryClose, queryForward, queryForward, queryOpen, queryReposition, queryReposition, queryRepositionByID, queryRepositionByID, removeRepositionListener, resetQuery, setBasicLogging, setBasicLogging, setCache, setCache, setDynamicPredicate, setErrorIfNull, setFetchOnReposition, setFillingBrowseRows, setIndexedReposition, setIterating, setLenientOffEnd, setParameterFilter, setPresort, unique, unique

Methods inherited from interface com.goldencode.p2j.persist.BufferCollection

addBuffer, addBuffer, addBuffer, addBuffer, bufferHandle, bufferHandle, bufferHandle, bufferHandle, bufferHandle, numBuffers, setBuffers, setBuffers, setBuffers

Methods inherited from interface com.goldencode.p2j.util.Openable

isOpen

Field Detail

sorter

private Presorter sorter

Helper which sorts preselected, unsorted results

cursorResults

private PresortCompoundQuery.CursorResults cursorResults

The cached results stored in the cursor, wrapped by Results interface.

Constructor Detail

PresortCompoundQuery

public PresortCompoundQuery()

Default constructor. Initialization is deferred until initialize() is called.

Method Detail

clearResults

public void clearResults()

Clear the current results from the query, so the same query instance can be executed again, without having to re-open it.

Specified by:

clearResults in interface P2JQuery

Overrides:

clearResults in class CompoundQuery

initialize

public PresortCompoundQuery initialize(boolean resolveOnce,
                                       boolean preselect)

Initialization logic.

This code is intentionally separated from the constructor. The purpose of this separation is to allow construction to occur in the prior scope while initialization can still occur within a method or lambda that is inside the next block's scope.

Overrides:

initialize in class CompoundQuery

Parameters:

resolveOnce - true to resolve arguments once, up front, or on every loop cycle.

preselect - true to force preselection of all results; false otherwise.

Returns:

This query instance.

initialize

public PresortCompoundQuery initialize()

Initialization logic.

This code is intentionally separated from the constructor. The purpose of this separation is to allow construction to occur in the prior scope while initialization can still occur within a method or lambda that is inside the next block's scope.

Returns:

This query instance.

initialize2f

public PresortCompoundQuery initialize2f()

Initialization logic.

This code is intentionally separated from the constructor. The purpose of this separation is to allow construction to occur in the prior scope while initialization can still occur within a method or lambda that is inside the next block's scope.

Overrides:

initialize2f in class CompoundQuery

Returns:

This query instance.

addComponent

public void addComponent(Joinable query,
                         int iteration,
                         boolean outer)

Add a joinable query to the compound query, and specify the nature of the iteration which will be performed (first, last, next, etc.) on that component, when the compound query is iterated. If this is not the first component to be added to the query, the type of join performed with the immediately previous component is determined by the value of outer.

Overrides:

addComponent in class CompoundQuery

Parameters:

query - Query which will perform the fundamental work for this component when the compound query is iterated.

iteration - A constant indicating the type of work to be performed upon an iteration of the compound query. This parameter determines whether the underlying query will be asked to perform a first, last, next, previous, or unique record retrieval.

outer - true if this component should be joined to the previously added component via a left outer join; false if an inner join is required. Note that adding an inner join component will cause any previously added components added as outer joins to be reset to inner joins.

Throws:

java.lang.IllegalStateException - if this method is invoked during an iteration cycle.

See Also:

CompoundQuery.iterate()

getRecordBuffers

public RecordBuffer[] getRecordBuffers()

Access the record buffers manipulated by this query, in order from left-most (outermost) table of the query's join (if any) to right-most (innermost) table.

Specified by:

getRecordBuffers in interface P2JQuery

Specified by:

getRecordBuffers in interface Presortable

Returns:

Array of one or more record buffers.

addSortCriterion

public void addSortCriterion(Resolvable sort)

Add a single sort criterion, in the form of a Resolvable object which is resolved at sort time. It is the value of the resolved result which is used for the sort.

The sort is ascending, from lowest resolved value to highest.

Specified by:

addSortCriterion in interface PresortDelegate

Parameters:

sort - A resolvable object whose resolved result is used for sorting.

addSortCriterion

public void addSortCriterion(Resolvable sort,
                             boolean descending)

Add a single sort criterion, in the form of a Resolvable object which is resolved at runtime. It is the value of the resolved result which is used for the sort.

Specified by:

addSortCriterion in interface PresortDelegate

Parameters:

sort - A resolvable object whose resolved result is used for sorting.

descending - if true, the sort is descending, from highest resolved value to lowest; otherwise, the sort is ascending.

addDynamicSortCriterion

public void addDynamicSortCriterion(Resolvable sort,
                                    boolean ascending)

Add a single dynamic sort criterion, in the form of a Resolvable object which is resolved at runtime. It is the value of the resolved result which is used for the sort.

Unlike addSortCriterion(com.goldencode.p2j.util.Resolvable) methods, the criterion is added with higher priority.

Specified by:

addDynamicSortCriterion in interface PresortDelegate

Parameters:

sort - A resolvable object whose resolved result is used for sorting.

ascending - if true, the sort is ascending, from lowest resolved value to highest; otherwise, the sort is descending.

clearDynamicSortCriteria

public void clearDynamicSortCriteria()

Clears all sort criteria added dynamically.

Specified by:

clearDynamicSortCriteria in interface PresortDelegate

enableBreakGroups

public void enableBreakGroups()

Enable all sort criteria set for this query to act as break group categories. When the query's results are presorted, the contents of each break group are determined.

Specified by:

enableBreakGroups in interface PresortDelegate

isFirst

public logical isFirst()

Determine whether the query result row currently being visited is the first row in the presorted results list.

Specified by:

isFirst in interface PresortDelegate

Returns:

true if the current result row is the first row, else false.

isFirstOfGroup

public logical isFirstOfGroup(Resolvable key)

Determine whether the query result row currently being visited is the first row within a break group whose category is identified by the specified resolvable object.

Specified by:

isFirstOfGroup in interface PresortDelegate

Parameters:

key - Break group category key. Must be the same object reference as was specified previously when invoking one of the addSortCriterion method variants.

Returns:

true if break groups are enabled and current row is first in the specified break group; false if break groups have not been enabled or current row is not first in the specified break group.

isFirstOfGroup

public logical isFirstOfGroup(integer level)

Determine whether the query result row currently being visited is the first row of the query's result set or the first row within a break group whose category is identified by the specified BREAK-BY level.

Specified by:

isFirstOfGroup in interface P2JQuery

Specified by:

isFirstOfGroup in interface PresortDelegate

Parameters:

level - Break group level, where 0 is the whole query, 1 is the first BREAK-BY sort criterion, etc. Must not be negative or greater than the number of sort criteria.

Returns:

true if the current row is first in the result set or within the specified break group; else false.

isFirstOfGroup

public logical isFirstOfGroup(int level)

Determine whether the query result row currently being visited is the first row of the query's result set or the first row within a break group whose category is identified by the specified BREAK-BY level.

Specified by:

isFirstOfGroup in interface P2JQuery

Parameters:

level - Break group level, where 0 is the whole query, 1 is the first BREAK-BY sort criterion, etc. Must not be negative or greater than the number of sort criteria.

Returns:

true if the current row is first in the result set or within the specified break group; else false.

isLast

public logical isLast()

Determine whether the query result row currently being visited is the last row in the presorted results list.

Specified by:

isLast in interface PresortDelegate

Returns:

true if the current result row is the last row, else false.

isPresort

public boolean isPresort()

Indicate whether the query is of presort type.

Specified by:

isPresort in interface P2JQuery

Overrides:

isPresort in class AbstractQuery

Returns:

true if the query is of presort type..

isLastOfGroup

public logical isLastOfGroup(Resolvable key)

Determine whether the query result row currently being visited is the last row within a break group whose category is identified by the specified resolvable object.

Specified by:

isLastOfGroup in interface PresortDelegate

Parameters:

key - Break group category key. Must be the same object reference as was specified previously when invoking one of the addSortCriterion method variants.

Returns:

true if break groups are enabled and current row is last in the specified break group; false if break groups have not been enabled or current row is not last in the specified break group.

isLastOfGroup

public logical isLastOfGroup(integer level)

Determine whether the query result row currently being visited is the last row of the query's result set or the last row within a break group whose category is identified by the specified BREAK-BY level.

Specified by:

isLastOfGroup in interface P2JQuery

Specified by:

isLastOfGroup in interface PresortDelegate

Parameters:

level - Break group level, where 0 is the whole query, 1 is the first BREAK-BY sort criterion, etc. Must not be negative or greater than the number of sort criteria. Must not be unknown value.

Returns:

true if the current row is last in the result set or within the specified break group; else false.

isLastOfGroup

public logical isLastOfGroup(int level)

Determine whether the query result row currently being visited is the last row of the query's result set or the last row within a break group whose category is identified by the specified BREAK-BY level.

Specified by:

isLastOfGroup in interface P2JQuery

Parameters:

level - Break group level, where 0 is the whole query, 1 is the first BREAK-BY sort criterion, etc. Must not be negative or greater than the number of sort criteria.

Returns:

true if the current row is last in the result set or within the specified break group; else false.

getSortedResults

public Results getSortedResults()

Access the current, sorted results for this query.

Specified by:

getSortedResults in interface Presortable

Returns:

Results object used to retrieve sorted results.

next

public boolean next(boolean iterating,
                    LockType lockType)

Retrieve the next virtual, composite row of results for the compound query, overriding the lock type to apply to each underlying query.

This is a combination of records retrieved by each component query. If the compound query involves outer joins, some of the underlying buffers may be empty when this method returns.

Overrides:

next in class CompoundQuery

Parameters:

iterating - true if this method is being invoked within the context of an iterating loop, which can only be exited by raising an end condition; false if end condition should not be raised, even if no further advancement of the composite result is possible.

lockType - Lock type which should override that of any underlying query.

Returns:

true if query could retrive the next record succefully; false if unsuccessful and lenientOffEnd is set on true.

Throws:

QueryOffEndException - if no more results were available in iterating mode.

ErrorConditionException - if an underlying query triggers an error.

isLastOfBreakGroup

protected boolean isLastOfBreakGroup(Resolvable key)

Determine whether the query result row currently being visited is the last row within a break group whose category is identified by the specified resolvable object.

Overrides:

isLastOfBreakGroup in class AbstractQuery

Parameters:

key - Break group category key. Must be the same object reference as was specified previously when invoking one of the addSortCriterion method variants.

Returns:

true if break groups are enabled and current row is last in the specified break group; false if break groups have not been enabled or current row is not last in the specified break group.

isNewBreakGroup

protected boolean isNewBreakGroup(Resolvable key)

Determine whether the query result row currently being visited is the first row within a break group whose category is identified by the specified resolvable object.

This is the backing worker method for isFirstOfGroup(com.goldencode.p2j.util.Resolvable) and is used internally by the query to manage accumulators.

Overrides:

isNewBreakGroup in class AbstractQuery

Parameters:

key - Break group category key. Must be the same object reference as was specified previously when invoking one of the addSortCriterion method variants.

Returns:

true if current row is first in a break group; false if it is not; unknown value if break groups have not been enabled.

isPresorted

protected boolean isPresorted()

Determines if the query is presorted, i.e. if the query is sorted up front in some special way.

Overrides:

isPresorted in class CompoundQuery

Returns:

true for this implementation.

cursorAsResults

protected PresortCompoundQuery.CursorResults cursorAsResults()

Get the cached results stored in the cursor, wrapped by Results interface.

Returns:

the cached results stored in the cursor, wrapped by Results interface.

presort

protected void presort()

Presort the results stored in the cursor.

Overrides:

presort in class CompoundQuery