org.apache.derby.impl.sql.execute

Class RowResultSet

java.lang.Object

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

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

org.apache.derby.impl.sql.execute.RowResultSet

All Implemented Interfaces:

CursorResultSet, NoPutResultSet, ResultSet, RowLocationRetRowSource, RowSource

class RowResultSet
extends NoPutResultSetImpl
implements CursorResultSet

Takes a constant row value and returns it as a result set.

This class actually probably never underlies a select statement, but in case it might and because it has the same behavior as the ones that do, we have it implement CursorResultSet and give reasonable answers.

Field Summary

Fields

Modifier and Type	Field and Description
private ExecRow	cachedRow
private boolean	canCacheRow
private boolean	next
private GeneratedMethod	row
int	rowsReturned

Fields inherited from class org.apache.derby.impl.sql.execute.NoPutResultSetImpl

checkNullCols, clonedExecRow, cncLen, resultSetNumber, targetResultSet

Fields inherited from class org.apache.derby.impl.sql.execute.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 org.apache.derby.iapi.sql.ResultSet

CURRENT_RESULTSET_ONLY, ENTIRE_RESULTSET_TREE, ISAFTERLAST, ISBEFOREFIRST, ISFIRST, ISLAST

Fields inherited from interface org.apache.derby.iapi.sql.execute.NoPutResultSet

ABSOLUTE, FIRST, LAST, NEXT, PREVIOUS, RELATIVE

Constructor Summary

Constructors

Constructor and Description
RowResultSet(Activation activation, ExecRow constantRow, boolean canCacheRow, int resultSetNumber, double optimizerEstimatedRowCount, double optimizerEstimatedCost)
RowResultSet(Activation activation, GeneratedMethod row, boolean canCacheRow, int resultSetNumber, double optimizerEstimatedRowCount, double optimizerEstimatedCost)

Method Summary

Modifier and Type	Method and Description
void	close() Close needs to invalidate any dependent statements, if this is a cursor.
ExecRow	getCurrentRow() This is not used in positioned update and delete, so just return a null.
ExecRow	getNextRowCore() If open and not returned yet, returns the row after plugging the parameters into the expressions.
RowLocation	getRowLocation() This is not operating against a stored table, so it has no row location to report.
long	getTimeSpent(int type) Return the total amount of time spent in this ResultSet
void	openCore() Sets state to 'open'.

Methods inherited from class org.apache.derby.impl.sql.execute.NoPutResultSetImpl

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

Methods inherited from class org.apache.derby.impl.sql.execute.BasicNoPutResultSetImpl

addWarning, attachStatementContext, checkCancellationFlag, checkRowPosition, cleanUp, dumpTimeStats, finish, 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, reopenCore, requiresRelocking, returnsRows, setAfterLastRow, setBeforeFirstRow, setCompactRow, setCompatRow

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.derby.iapi.sql.ResultSet

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

Field Detail

rowsReturned

public int rowsReturned

canCacheRow

private boolean canCacheRow

next

private boolean next

row

private GeneratedMethod row

cachedRow

private ExecRow cachedRow

Constructor Detail

RowResultSet

RowResultSet(Activation activation,
             GeneratedMethod row,
             boolean canCacheRow,
             int resultSetNumber,
             double optimizerEstimatedRowCount,
             double optimizerEstimatedCost)

RowResultSet

RowResultSet(Activation activation,
             ExecRow constantRow,
             boolean canCacheRow,
             int resultSetNumber,
             double optimizerEstimatedRowCount,
             double optimizerEstimatedCost)

Method Detail

openCore

public void openCore()
              throws StandardException

Sets state to 'open'.

Specified by:

openCore in interface NoPutResultSet

Throws:

StandardException - thrown if activation closed.

getNextRowCore

public ExecRow getNextRowCore()
                       throws StandardException

If open and not returned yet, returns the row after plugging the parameters into the expressions.

Specified by:

getNextRowCore in interface NoPutResultSet

Specified by:

getNextRowCore in class BasicNoPutResultSetImpl

Returns:

the next row in the result

Throws:

StandardException - thrown on failure.

See Also:

NoPutResultSet.getNextRowCore()

close

public void close()
           throws StandardException

Description copied from class: NoPutResultSetImpl

Close needs to invalidate any dependent statements, if this is a cursor. Must be called by any subclasses that override close().

Specified by:

close in interface ResultSet

Overrides:

close in class NoPutResultSetImpl

Throws:

StandardException - thrown on error

See Also:

ResultSet.close()

getTimeSpent

public long getTimeSpent(int type)

Return the total amount of time spent in this ResultSet

Specified by:

getTimeSpent in interface ResultSet

Parameters:

type - CURRENT_RESULTSET_ONLY - time spent only in this ResultSet ENTIRE_RESULTSET_TREE - time spent in this ResultSet and below.

Returns:

long The total amount of time spent (in milliseconds).

getRowLocation

public RowLocation getRowLocation()

This is not operating against a stored table, so it has no row location to report.

Specified by:

getRowLocation in interface CursorResultSet

Returns:

a null.

See Also:

CursorResultSet

getCurrentRow

public ExecRow getCurrentRow()

This is not used in positioned update and delete, so just return a null.

Specified by:

getCurrentRow in interface CursorResultSet

Returns:

a null.

See Also:

CursorResultSet