org.apache.derby.impl.sql.execute
Class MiscResultSet

java.lang.Object
  org.apache.derby.impl.sql.execute.NoRowsResultSetImpl
      org.apache.derby.impl.sql.execute.MiscResultSet

All Implemented Interfaces:

ResultSet

Direct Known Subclasses:

SetTransactionResultSet

class MiscResultSet

extends NoRowsResultSetImpl

This is a wrapper class which invokes the Execution-time logic for Misc statements. The real Execution-time logic lives inside the executeConstantAction() method of the Execution constant.

Author:

jamie

Field Summary

protected Activation	activation
protected long	beginExecutionTime
protected long	beginTime
private ConstantAction	constantAction
protected long	endExecutionTime
protected long	endTime
protected java.lang.String	indent
protected LanguageConnectionContext	lcc
protected int	sourceDepth
protected java.lang.String	subIndent
protected NoPutResultSet[]	subqueryTrackingArray

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

CURRENT_RESULTSET_ONLY, ENTIRE_RESULTSET_TREE, ISAFTERLAST, ISBEFOREFIRST, ISFIRST, ISLAST

Constructor Summary

(package private)

MiscResultSet(Activation activation) Construct a MiscResultSet

Method Summary

boolean	checkRowPosition(int isType) Determine if the cursor is before the first row in the result set.
void	cleanUp() Tells the system to clean up on an error.
void	close() No rows to return, does nothing
boolean	doesCommit() Does this ResultSet cause a commit or rollback.
static void	evaluateACheckConstraint(GeneratedMethod checkGM, java.lang.String checkName, long heapConglom, Activation activation) Run a check constraint against the current row.
static void	evaluateCheckConstraints(GeneratedMethod checkGM, Activation activation) Run check constraints against the current row.
void	finish() doesn't need to do anything, as no calls are made that need to be restricted once the result set is 'finished'.
ExecRow	getAbsoluteRow(int row) Returns the row at the absolute position from the query, and returns NULL when there is no such position.
ResultSet	getAutoGeneratedKeysResultset() ResultSet for rows inserted into the table (contains auto-generated keys columns only)
java.sql.Timestamp	getBeginExecutionTimestamp() Get the Timestamp for the beginning of execution.
protected long	getCurrentTimeMillis() Return the current time in milliseconds, if DEBUG and RunTimeStats is on, else return 0.
java.lang.String	getCursorName() Return the cursor name, null in this case.
java.sql.Timestamp	getEndExecutionTimestamp() Get the Timestamp for the end of execution.
long	getExecuteTime() Get the execution time in milliseconds.
ExecRow	getFirstRow() Returns the first row from the query, and returns NULL when there are no rows.
ExecRow	getLastRow() Returns the last row from the query, and returns NULL when there are no rows.
ExecRow	getNextRow() No rows to return, so throw an exception.
ExecRow	getPreviousRow() Returns the previous row from the query, and returns NULL when there are no more previous rows.
java.lang.String	getQueryPlanText(int depth) RESOLVE - This method will go away once it is overloaded in all subclasses.
ExecRow	getRelativeRow(int row) Returns the row at the relative position from the current cursor position, and returns NULL when there is no such position.
ResultDescription	getResultDescription() Returns null.
int	getRowNumber() Returns the row number of the current row.
NoPutResultSet[]	getSubqueryTrackingArray(int numSubqueries) Get the subquery ResultSet tracking array from the top ResultSet.
long	getTimeSpent(int type) Return the total amount of time spent in this ResultSet
java.sql.SQLWarning	getWarnings() Return the set of warnings generated during the execution of this result set.
boolean	isClosed() Just report that it is always closed.
int	modifiedRowCount() Returns zero.
void	open() Needs to be called before the result set will do anything.
boolean	returnsRows() Returns FALSE
ExecRow	setAfterLastRow() Sets the current position to after the last row and returns NULL because there is no current row.
ExecRow	setBeforeFirstRow() Sets the current position to before the first row and returns NULL because there is no current row.

Methods inherited from class java.lang.Object

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

Field Detail

constantAction

private final ConstantAction constantAction

activation

protected final Activation activation

subqueryTrackingArray

protected NoPutResultSet[] subqueryTrackingArray

indent

protected java.lang.String indent

subIndent

protected java.lang.String subIndent

sourceDepth

protected int sourceDepth

lcc

protected final LanguageConnectionContext lcc

beginTime

protected long beginTime

endTime

protected long endTime

beginExecutionTime

protected long beginExecutionTime

endExecutionTime

protected long endExecutionTime

Constructor Detail

MiscResultSet

MiscResultSet(Activation activation)
        throws StandardException

Construct a MiscResultSet

Parameters:

activation - Describes run-time environment.

Throws:

StandardException - Standard Cloudscape error policy.

Method Detail

open

public void open()
          throws StandardException

Description copied from interface: ResultSet

Needs to be called before the result set will do anything. Need to call before getNextRow(), or for a result set that doesn't return rows, this is the call that will cause all the work to be done.

Returns:

Nothing

Throws:

StandardException - Thrown on failure

cleanUp

public void cleanUp()

Description copied from interface: ResultSet

Tells the system to clean up on an error.

Returns:

Nothing

See Also:

ResultSet.cleanUp()

returnsRows

public final boolean returnsRows()

Returns FALSE

Specified by:

returnsRows in interface ResultSet

Returns:

TRUE if the statement returns rows, FALSE if not.

modifiedRowCount

public int modifiedRowCount()

Returns zero.

Specified by:

modifiedRowCount in interface ResultSet

Returns:

The number of rows affect by the statement, so far.

getResultDescription

public ResultDescription getResultDescription()

Returns null.

Specified by:

getResultDescription in interface ResultSet

Returns:

A ResultDescription describing the results of the statement.

getAbsoluteRow

public ExecRow getAbsoluteRow(int row)
                       throws StandardException

Returns the row at the absolute position from the query, and returns NULL when there is no such position. (Negative position means from the end of the result set.) Moving the cursor to an invalid position leaves the cursor positioned either before the first row (negative position) or after the last row (positive position). NOTE: An exception will be thrown on 0.

Specified by:

getAbsoluteRow in interface ResultSet

Parameters:

row - The position.

Returns:

The row at the absolute position, or NULL if no such position.

Throws:

StandardException - Thrown on failure

See Also:

Row

getRelativeRow

public ExecRow getRelativeRow(int row)
                       throws StandardException

Returns the row at the relative position from the current cursor position, and returns NULL when there is no such position. (Negative position means toward the beginning of the result set.) Moving the cursor to an invalid position leaves the cursor positioned either before the first row (negative position) or after the last row (positive position). NOTE: 0 is valid. NOTE: An exception is thrown if the cursor is not currently positioned on a row.

Specified by:

getRelativeRow in interface ResultSet

Parameters:

row - The position.

Returns:

The row at the relative position, or NULL if no such position.

Throws:

StandardException - Thrown on failure

See Also:

Row

setBeforeFirstRow

public ExecRow setBeforeFirstRow()
                          throws StandardException

Sets the current position to before the first row and returns NULL because there is no current row.

Specified by:

setBeforeFirstRow in interface ResultSet

Returns:

NULL.

Throws:

StandardException - Thrown on failure

See Also:

Row

getFirstRow

public ExecRow getFirstRow()
                    throws StandardException

Returns the first row from the query, and returns NULL when there are no rows.

Specified by:

getFirstRow in interface ResultSet

Returns:

The first row, or NULL if no rows.

Throws:

StandardException - Thrown on failure

See Also:

Row

getNextRow

public ExecRow getNextRow()
                   throws StandardException

No rows to return, so throw an exception.

Specified by:

getNextRow in interface ResultSet

Returns:

The next row, or NULL if no more rows.

Throws:

StandardException - Always throws a StandardException to indicate that this method is not intended to be used.

See Also:

Row

getPreviousRow

public ExecRow getPreviousRow()
                       throws StandardException

Returns the previous row from the query, and returns NULL when there are no more previous rows.

Specified by:

getPreviousRow in interface ResultSet

Returns:

The previous row, or NULL if no more previous rows.

Throws:

StandardException - Thrown on failure

See Also:

Row

getLastRow

public ExecRow getLastRow()
                   throws StandardException

Returns the last row from the query, and returns NULL when there are no rows.

Specified by:

getLastRow in interface ResultSet

Returns:

The last row, or NULL if no rows.

Throws:

StandardException - Thrown on failure

See Also:

Row

setAfterLastRow

public ExecRow setAfterLastRow()
                        throws StandardException

Sets the current position to after the last row and returns NULL because there is no current row.

Specified by:

setAfterLastRow in interface ResultSet

Returns:

NULL.

Throws:

StandardException - Thrown on failure

See Also:

Row

checkRowPosition

public boolean checkRowPosition(int isType)

Determine if the cursor is before the first row in the result set.

Specified by:

checkRowPosition in interface ResultSet

Returns:

true if before the first row, false otherwise. Returns false when the result set contains no rows.

getRowNumber

public int getRowNumber()

Returns the row number of the current row. Row numbers start from 1 and go to 'n'. Corresponds to row numbering used to position current row in the result set (as per JDBC).

Specified by:

getRowNumber in interface ResultSet

Returns:

the row number, or 0 if not on a row

close

public void close()
           throws StandardException

No rows to return, does nothing

Specified by:

close in interface ResultSet

Returns:

Nothing

Throws:

StandardException - thrown on error

isClosed

public boolean isClosed()

Just report that it is always closed. RESOLVE: if we don't report that we are closed, then we will wind up with a dependency problem when we send an invalidateFor on our own Statement. It will call lcc.verifyNoOpenResultSets(), which is really supposed to be verify that there are no read only result sets that are open.

Specified by:

isClosed in interface ResultSet

Returns:

true if the ResultSet has been closed.

finish

public void finish()
            throws StandardException

doesn't need to do anything, as no calls are made that need to be restricted once the result set is 'finished'.

Specified by:

finish in interface ResultSet

Returns:

Nothing

Throws:

StandardException - on error

getExecuteTime

public long getExecuteTime()

Get the execution time in milliseconds.

Specified by:

getExecuteTime in interface ResultSet

Returns:

long The execution time in milliseconds.

getBeginExecutionTimestamp

public java.sql.Timestamp getBeginExecutionTimestamp()

Get the Timestamp for the beginning of execution.

Specified by:

getBeginExecutionTimestamp in interface ResultSet

Returns:

Timestamp The Timestamp for the beginning of execution.

getEndExecutionTimestamp

public java.sql.Timestamp getEndExecutionTimestamp()

Get the Timestamp for the end of execution.

Specified by:

getEndExecutionTimestamp in interface ResultSet

Returns:

Timestamp The Timestamp for the end of execution.

getQueryPlanText

public java.lang.String getQueryPlanText(int depth)

RESOLVE - This method will go away once it is overloaded in all subclasses. Return the query plan as a String.

Parameters:

depth - Indentation level.

Returns:

String The query plan as a String.

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).

getSubqueryTrackingArray

public final NoPutResultSet[] getSubqueryTrackingArray(int numSubqueries)

Description copied from interface: ResultSet

Get the subquery ResultSet tracking array from the top ResultSet. (Used for tracking open subqueries when closing down on an error.)

Specified by:

getSubqueryTrackingArray in interface ResultSet

Parameters:

numSubqueries - The size of the array (For allocation on demand.)

Returns:

NoPutResultSet[] Array of NoPutResultSets for subqueries.

See Also:

ResultSet.getSubqueryTrackingArray(int)

getAutoGeneratedKeysResultset

public ResultSet getAutoGeneratedKeysResultset()

Description copied from interface: ResultSet

ResultSet for rows inserted into the table (contains auto-generated keys columns only)

Specified by:

getAutoGeneratedKeysResultset in interface ResultSet

Returns:

NoPutResultSet NoPutResultSets for rows inserted into the table.

See Also:

ResultSet.getAutoGeneratedKeysResultset()

getCursorName

public java.lang.String getCursorName()

Return the cursor name, null in this case.

Specified by:

getCursorName in interface ResultSet

Returns:

A String with the name of the cursor, if any. Returns NULL if this is not a cursor statement.

See Also:

ResultSet.getCursorName()

getCurrentTimeMillis

protected final long getCurrentTimeMillis()

Return the current time in milliseconds, if DEBUG and RunTimeStats is on, else return 0. (Only pay price of system call if need to.)

Returns:

long Current time in milliseconds.

evaluateACheckConstraint

public static void evaluateACheckConstraint(GeneratedMethod checkGM,
                                            java.lang.String checkName,
                                            long heapConglom,
                                            Activation activation)
                                     throws StandardException

Run a check constraint against the current row. Raise an error if the check constraint is violated.

Parameters:

checkGM - Generated code to run the check constraint.

checkName - Name of the constraint to check.

heapConglom - Number of heap conglomerate.

Throws:

StandardException - thrown on error

evaluateCheckConstraints

public static void evaluateCheckConstraints(GeneratedMethod checkGM,
                                            Activation activation)
                                     throws StandardException

Run check constraints against the current row. Raise an error if a check constraint is violated.

Parameters:

checkGM - Generated code to run the check constraint.

Throws:

StandardException - thrown on error

doesCommit

public boolean doesCommit()

Does this ResultSet cause a commit or rollback.

Returns:

Whether or not this ResultSet cause a commit or rollback.

getWarnings

public java.sql.SQLWarning getWarnings()

Description copied from interface: ResultSet

Return the set of warnings generated during the execution of this result set. The warnings are cleared once this call returns.

Specified by:

getWarnings in interface ResultSet