Package org.apache.derby.impl.sql.execute

Class MatchingClauseConstantAction

java.lang.Object

org.apache.derby.impl.sql.execute.MatchingClauseConstantAction

All Implemented Interfaces:

Externalizable, Serializable, Formatable, TypedFormat, ConstantAction

public class MatchingClauseConstantAction
extends Object
implements ConstantAction, Formatable

Describes the execution machinery needed to evaluate a WHEN [ NOT ] MATCHING clause of a MERGE statement.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
private String	_actionMethodName
private ResultSet	_actionRS
private int	_clauseType
private GeneratedMethod	_matchRefinementMethod
private String	_matchRefinementName
private String	_resultSetFieldName
private GeneratedMethod	_rowMakingMethod
private String	_rowMakingMethodName
private ConstantAction	_thenAction
private ResultDescription	_thenColumnSignature
private static final int	FIRST_VERSION
private static final long	serialVersionUID	Serial version produced by the serialver utility.

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

WHEN_MATCHED_THEN_DELETE, WHEN_MATCHED_THEN_UPDATE, WHEN_NOT_MATCHED_THEN_INSERT

Constructor Summary

Constructors

Constructor	Description
MatchingClauseConstantAction()	0-arg constructor needed by Formatable machinery
MatchingClauseConstantAction(int clauseType, String matchRefinementName, ResultDescription thenColumnSignature, String rowMakingMethodName, String resultSetFieldName, String actionMethodName, ConstantAction thenAction)	Construct from thin air.

Method Summary

Modifier and Type	Method	Description
private ExecRow	bufferThenRow(Activation activation)	Construct and buffer a row for the INSERT/UPDATE/DELETE action corresponding to this [ NOT ] MATCHED clause.
(package private) TemporaryRowHolderImpl	bufferThenRow(Activation activation, TemporaryRowHolderImpl thenRows, ExecRow selectRow)	Construct and buffer a row for the INSERT/UPDATE/DELETE action corresponding to this [ NOT ] MATCHED clause.
int	clauseType()	Get the clause type: WHEN_NOT_MATCHED_THEN_INSERT, WHEN_MATCHED_THEN_UPDATE, WHEN_MATCHED_THEN_DELETE
(package private) void	cleanUp()	Release resources at the end.
private TemporaryRowHolderImpl	createThenRows(Activation activation)	Create the temporary table for holding the rows which are buffered up for bulk-processing after the driving left join completes.
(package private) boolean	evaluateRefinementClause(Activation activation)	Run the matching refinement clause associated with this WHEN [ NOT ] MATCHED clause.
void	executeConstantAction(Activation activation)	Run the ConstantAction.
void	executeConstantAction(Activation activation, TemporaryRowHolderImpl thenRows)
int	getTypeFormatId()	Get the formatID which corresponds to this class.
(package private) void	init()	Initialize this constant action, nulling out any transient state left over from a previous use.
void	readExternal(ObjectInput in)	Read this object from a stream of stored objects.
void	writeExternal(ObjectOutput out)	Write this object to a stream of stored objects.

Methods inherited from class java.lang.Object

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

Field Details

serialVersionUID

private static final long serialVersionUID

Serial version produced by the serialver utility. Needed in order to make serialization work reliably across different compilers.

See Also:

• Constant Field Values

FIRST_VERSION

private static final int FIRST_VERSION

See Also:

• Constant Field Values

_clauseType

private int _clauseType

_matchRefinementName

private String _matchRefinementName

_thenColumnSignature

private ResultDescription _thenColumnSignature

_rowMakingMethodName

private String _rowMakingMethodName

_resultSetFieldName

private String _resultSetFieldName

_actionMethodName

private String _actionMethodName

_thenAction

private ConstantAction _thenAction

_matchRefinementMethod

private transient GeneratedMethod _matchRefinementMethod

_rowMakingMethod

private transient GeneratedMethod _rowMakingMethod

_actionRS

private transient ResultSet _actionRS

Constructor Details

MatchingClauseConstantAction

public MatchingClauseConstantAction()

0-arg constructor needed by Formatable machinery

MatchingClauseConstantAction

public MatchingClauseConstantAction(int clauseType,
 String matchRefinementName,
 ResultDescription thenColumnSignature,
 String rowMakingMethodName,
 String resultSetFieldName,
 String actionMethodName,
 ConstantAction thenAction)

Construct from thin air.

Parameters:

clauseType - WHEN_NOT_MATCHED_THEN_INSERT, WHEN_MATCHED_THEN_UPDATE, WHEN_MATCHED_THEN_DELETE

matchRefinementName - Name of the method which evaluates the boolean expression in the WHEN clause.

thenColumnSignature - The shape of the row which goes into the temporary table.

rowMakingMethodName - Name of the method which populates the "then" row with expressions from the driving left join.

resultSetFieldName - Name of the field which will be stuffed at runtime with the temporary table of relevant rows.

actionMethodName - Name of the method which invokes the INSERT/UPDATE/DELETE action.

thenAction - The ConstantAction describing the associated INSERT/UPDATE/DELETE action.

Method Details

clauseType

public int clauseType()

Get the clause type: WHEN_NOT_MATCHED_THEN_INSERT, WHEN_MATCHED_THEN_UPDATE, WHEN_MATCHED_THEN_DELETE

executeConstantAction

public void executeConstantAction(Activation activation)
                           throws StandardException

Description copied from interface: ConstantAction

Run the ConstantAction.

Specified by:

executeConstantAction in interface ConstantAction

Parameters:

activation - The execution environment for this constant action.

Throws:

StandardException - Thrown on failure

executeConstantAction

public void executeConstantAction(Activation activation,
 TemporaryRowHolderImpl thenRows)
                           throws StandardException

Throws:

StandardException

init

void init()
   throws StandardException

Initialize this constant action, nulling out any transient state left over from a previous use.

Throws:

StandardException

evaluateRefinementClause

boolean evaluateRefinementClause(Activation activation)
                          throws StandardException

Run the matching refinement clause associated with this WHEN [ NOT ] MATCHED clause. The refinement is a boolean expression. Return the boolean value it resolves to. A boolean NULL is treated as false. If there is no refinement clause, then this method evaluates to true.

Throws:

StandardException

bufferThenRow

TemporaryRowHolderImpl bufferThenRow(Activation activation,
 TemporaryRowHolderImpl thenRows,
 ExecRow selectRow)
                              throws StandardException

Construct and buffer a row for the INSERT/UPDATE/DELETE action corresponding to this [ NOT ] MATCHED clause. The buffered row is built from columns in the passed-in row. The passed-in row is the SELECT list of the MERGE statement's driving left join.

Throws:

StandardException

cleanUp

void cleanUp()
      throws StandardException

Release resources at the end.

Throws:

StandardException

bufferThenRow

private ExecRow bufferThenRow(Activation activation)
                       throws StandardException

Construct and buffer a row for the INSERT/UPDATE/DELETE action corresponding to this [ NOT ] MATCHED clause.

Throws:

StandardException

createThenRows

private TemporaryRowHolderImpl createThenRows(Activation activation)
                                       throws StandardException

Create the temporary table for holding the rows which are buffered up for bulk-processing after the driving left join completes.

Throws:

StandardException

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
ClassNotFoundException

Read this object from a stream of stored objects.

Specified by:

readExternal in interface Externalizable

Parameters:

in - read this.

Throws:

IOException - thrown on error

ClassNotFoundException - thrown on error

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Write this object to a stream of stored objects.

Specified by:

writeExternal in interface Externalizable

Parameters:

out - write bytes here.

Throws:

IOException - thrown on error

getTypeFormatId

public int getTypeFormatId()

Get the formatID which corresponds to this class.

Specified by:

getTypeFormatId in interface TypedFormat

Returns:

the formatID of this class