Class NestedLoopLeftOuterJoinResultSet

java.lang.Object

org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl

org.apache.derby.impl.sql.execute.NoPutResultSetImpl

org.apache.derby.impl.sql.execute.JoinResultSet

org.apache.derby.impl.sql.execute.NestedLoopJoinResultSet

org.apache.derby.impl.sql.execute.NestedLoopLeftOuterJoinResultSet

All Implemented Interfaces:

CursorResultSet, NoPutResultSet, ResultSet, RowLocationRetRowSource, RowSource

Direct Known Subclasses:

HashLeftOuterJoinResultSet

class NestedLoopLeftOuterJoinResultSet
extends NestedLoopJoinResultSet

Takes 2 NoPutResultSets and a join filter and returns the join's rows satisfying the filter as a result set plus the rows from the left joined with a null row from the right when there is no matching row in the right result set.

Nested Class Summary

Nested classes/interfaces inherited from class BasicNoPutResultSetImpl

BasicNoPutResultSetImpl.FieldComparator

Field Summary

Fields

Modifier and Type	Field	Description
int	emptyRightRowsReturned
protected GeneratedMethod	emptyRowFun
private boolean	matchRight
private boolean	returnedEmptyRight
private ExecRow	rightEmptyRow
private boolean	wasRightOuterJoin

Fields inherited from class JoinResultSet

isRightOpen, leftNumCols, leftResultSet, leftRow, mergedRow, notExistsRightSide, oneRowRightSide, restriction, restrictionTime, rightNumCols, rightResultSet, rightRow, rowsReturned, rowsSeenLeft, rowsSeenRight, userSuppliedOptimizerOverrides

Fields inherited from class NoPutResultSetImpl

checkNullCols, clonedExecRow, cncLen, resultSetNumber, targetResultSet

Fields inherited from class BasicNoPutResultSetImpl

activation, beginTime, closeTime, compactRow, constructorTime, currentRow, endExecutionTime, finished, isOpen, isTopResultSet, nextTime, numOpens, openTime, optimizerEstimatedCost, optimizerEstimatedRowCount, resultDescription, rowsFiltered, rowsSeen, startExecutionTime, subqueryTrackingArray

Fields inherited from interface NoPutResultSet

ABSOLUTE, FIRST, LAST, NEXT, PREVIOUS, RELATIVE, TEMPORARY_RESULT_SET_NUMBER

Fields inherited from interface ResultSet

CURRENT_RESULTSET_ONLY, ENTIRE_RESULTSET_TREE, ISAFTERLAST, ISBEFOREFIRST, ISFIRST, ISLAST

Constructor Summary

Constructors

Constructor

Description

NestedLoopLeftOuterJoinResultSet(NoPutResultSet leftResultSet, int leftNumCols, NoPutResultSet rightResultSet, int rightNumCols, Activation activation, GeneratedMethod restriction, int resultSetNumber, GeneratedMethod emptyRowFun, boolean wasRightOuterJoin, boolean oneRowRightSide, boolean notExistsRightSide, double optimizerEstimatedRowCount, double optimizerEstimatedCost, String userSuppliedOptimizerOverrides)

Method Summary

Modifier and Type	Method	Description
(package private) void	clearScanState()	Clear any private state that changes during scans.
protected void	getMergedRow(ExecRow leftRow, ExecRow rightRow)
ExecRow	getNextRowCore()	Return the requested values computed from the next row (if any) for which the restriction evaluates to true.

Methods inherited from class NestedLoopJoinResultSet

close, getTimeSpent

Methods inherited from class JoinResultSet

closeRight, finish, getCurrentRow, getRowLocation, openCore, openRight, reopenCore

Methods inherited from class NoPutResultSetImpl

clearCurrentRow, clearOrderableCache, closeRowSource, getCursorName, getNextRowFromRowSource, getResultDescription, getValidColumns, isForUpdate, markRowAsDeleted, needsRowLocation, needsRowLocationForDeferredCheckConstraints, needsToClone, offendingRowLocation, positionScanAtRowLocation, printQualifiers, resultSetNumber, rowLocation, setCurrentRow, setHasDeferrableChecks, setNeedsRowLocation, setTargetResultSet, skipRow, skipScan, unpackHashValue, updateRow

Methods inherited from class BasicNoPutResultSetImpl

addWarning, attachStatementContext, checkCancellationFlag, checkRowPosition, childrenToXML, cleanUp, dumpTimeStats, finishAndRTS, getAbsoluteRow, getActivation, getAutoGeneratedKeysResultset, getBeginExecutionTimestamp, getCompactRow, getCurrentTimeMillis, getElapsedMillis, getEndExecutionTimestamp, getEstimatedRowCount, getExecuteTime, getExecutionFactory, getFirstRow, getLanguageConnectionContext, getLastRow, getNextRow, getPointOfAttachment, getPreviousRow, getRelativeRow, getRowNumber, getScanIsolationLevel, getSubqueryTrackingArray, getTransactionController, getWarnings, isClosed, isXplainOnlyMode, markAsTopResultSet, modifiedRowCount, open, recordConstructorTime, requiresRelocking, returnsRows, setAfterLastRow, setBeforeFirstRow, setCompactRow, setCompatRow, toXML, toXML

Methods inherited from class Object

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

Methods inherited from interface ResultSet

addWarning, checkRowPosition, cleanUp, clearCurrentRow, getAbsoluteRow, getActivation, getAutoGeneratedKeysResultset, getBeginExecutionTimestamp, getCursorName, getEndExecutionTimestamp, getExecuteTime, getFirstRow, getLastRow, getNextRow, getPreviousRow, getRelativeRow, getResultDescription, getRowNumber, getSubqueryTrackingArray, getWarnings, isClosed, modifiedRowCount, open, returnsRows, setAfterLastRow, setBeforeFirstRow, toXML

Field Details

emptyRowFun

protected GeneratedMethod emptyRowFun

wasRightOuterJoin

private boolean wasRightOuterJoin

matchRight

private boolean matchRight

returnedEmptyRight

private boolean returnedEmptyRight

rightEmptyRow

private ExecRow rightEmptyRow

emptyRightRowsReturned

public int emptyRightRowsReturned

Constructor Details

NestedLoopLeftOuterJoinResultSet

NestedLoopLeftOuterJoinResultSet(NoPutResultSet leftResultSet,
 int leftNumCols,
 NoPutResultSet rightResultSet,
 int rightNumCols,
 Activation activation,
 GeneratedMethod restriction,
 int resultSetNumber,
 GeneratedMethod emptyRowFun,
 boolean wasRightOuterJoin,
 boolean oneRowRightSide,
 boolean notExistsRightSide,
 double optimizerEstimatedRowCount,
 double optimizerEstimatedCost,
 String userSuppliedOptimizerOverrides)

Method Details

getNextRowCore

public ExecRow getNextRowCore()
                       throws StandardException

Return the requested values computed from the next row (if any) for which the restriction evaluates to true.

restriction parameters are evaluated for each row.

Specified by:

getNextRowCore in interface NoPutResultSet

Overrides:

getNextRowCore in class NestedLoopJoinResultSet

Returns:

the next row in the join result

Throws:

StandardException - Thrown on error

StandardException - ResultSetNotOpen thrown if closed

See Also:

• NoPutResultSet.getNextRowCore()

getMergedRow

protected void getMergedRow(ExecRow leftRow,
 ExecRow rightRow)
                     throws StandardException

Throws:

StandardException

clearScanState

void clearScanState()

Clear any private state that changes during scans. This includes things like the last row seen, etc. THis does not include immutable things that are typically set up in the constructor.

This method is called on open()/close() and reopen()

WARNING: this should be implemented in every sub class and it should always call super.clearScanState().

Overrides:

clearScanState in class NestedLoopJoinResultSet