Class GenerationClauseNode

java.lang.Object

org.apache.derby.impl.sql.compile.QueryTreeNode

org.apache.derby.impl.sql.compile.ValueNode

org.apache.derby.impl.sql.compile.GenerationClauseNode

All Implemented Interfaces:

Visitable

class GenerationClauseNode
extends ValueNode

This node describes a Generation Clause in a column definition.

Field Summary

Fields

Modifier and Type	Field	Description
private ProviderList	_apl
private ValueNode	_boundExpression
private String	_expressionText
private ValueNode	_generationExpression	////////////////////////////////////////////////////////////////////////////////

Fields inherited from class ValueNode

transformed

Fields inherited from class QueryTreeNode

AUTOINCREMENT_CREATE_MODIFY, AUTOINCREMENT_CYCLE, AUTOINCREMENT_INC_INDEX, AUTOINCREMENT_IS_AUTOINCREMENT_INDEX, AUTOINCREMENT_START_INDEX

Constructor Summary

Constructors

Constructor	Description
GenerationClauseNode(ValueNode generationExpression, String expressionText, ContextManager cm)	////////////////////////////////////////////////////////////////////////////////

Method Summary

Modifier and Type	Method	Description
(package private) void	acceptChildren(Visitor v)	Accept the visitor for all visitable children of this node.
(package private) ValueNode	bindExpression(FromList fromList, SubqueryList subqueryList, List<AggregateNode> aggregates)	Binding the generation clause.
List<ColumnReference>	findReferencedColumns()	Return a list of columns referenced in the generation expression.
(package private) void	generateExpression(ExpressionClassBuilder acb, MethodBuilder mb)	Generate code for this node.
(package private) ProviderList	getAuxiliaryProviderList()	Return the auxiliary provider list.
String	getExpressionText()	Get the defining text of this generation clause
(package private) boolean	isEquivalent(ValueNode other)	Tests if this node is equivalent to the specified ValueNode.
(package private) void	printSubNodes(int depth)	Prints the sub-nodes of this object.
(package private) void	setAuxiliaryProviderList(ProviderList apl)	Set the auxiliary provider list.
String	toString()	Convert this object to a String.

Methods inherited from class ValueNode

bindExpression, categorize, changeToCNF, checkIsBoolean, checkTopPredicatesForEqualsConditions, constantExpression, copyFields, eliminateNots, evaluateConstantExpressions, genEqualsFalseTree, generate, genIsNullTree, genSQLJavaSQLTree, getClone, getColumnName, getConstantValueAsObject, getDataValueFactory, getOrderableVariantType, getSchemaName, getSourceResultColumn, getTableName, getTablesReferenced, getTransformed, getTypeCompiler, getTypeId, getTypeServices, isBinaryEqualsOperatorNode, isBooleanFalse, isBooleanTrue, isCloneable, isConstantExpression, isInListProbeNode, isParameterNode, isRelationalOperator, isSameNodeKind, optimizableEqualityNode, preprocess, putAndsOnTop, remapColumnReferencesToExpressions, requiresTypeFromContext, selectivity, setCollationInfo, setCollationInfo, setCollationUsingCompilationSchema, setCollationUsingCompilationSchema, setNullability, setTransformed, setType, setType, setType, updatableByCursor, verifyChangeToCNF, verifyEliminateNots, verifyPutAndsOnTop

Methods inherited from class QueryTreeNode

accept, addTag, addUDTUsagePriv, addUDTUsagePriv, bindOffsetFetch, bindRowMultiSet, bindUserCatalogType, bindUserType, checkReliability, checkReliability, convertDefaultNode, copyTagsFrom, createTypeDependency, debugFlush, debugPrint, disablePrivilegeCollection, formatNodeString, generateAuthorizeCheck, getBeginOffset, getClassFactory, getCompilerContext, getContext, getContextManager, getDataDictionary, getDependencyManager, getEndOffset, getExecutionFactory, getGenericConstantActionFactory, getIntProperty, getLanguageConnectionContext, getLongProperty, getNullNode, getOffsetOrderedNodes, getOptimizerFactory, getOptimizerTracer, getParameterTypes, getSchemaDescriptor, getSchemaDescriptor, getStatementType, getTableDescriptor, getTypeCompiler, getUDTDesc, isAtomic, isPrivilegeCollectionRequired, isSessionSchema, isSessionSchema, makeConstantAction, makeTableName, makeTableName, nodeHeader, optimizerTracingIsOn, orReliability, parseSearchCondition, parseStatement, printLabel, referencesSessionSchema, resolveTableToSynonym, setBeginOffset, setEndOffset, setRefActionInfo, stackPrint, taggedWith, treePrint, treePrint, verifyClassExist

Methods inherited from class Object

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

Field Details

_generationExpression

private ValueNode _generationExpression

////////////////////////////////////////////////////////////////////////////////

_expressionText

private String _expressionText

_boundExpression

private ValueNode _boundExpression

_apl

private ProviderList _apl

Constructor Details

GenerationClauseNode

GenerationClauseNode(ValueNode generationExpression,
 String expressionText,
 ContextManager cm)

////////////////////////////////////////////////////////////////////////////////

Method Details

getExpressionText

public String getExpressionText()

Get the defining text of this generation clause

setAuxiliaryProviderList

void setAuxiliaryProviderList(ProviderList apl)

Set the auxiliary provider list.

getAuxiliaryProviderList

ProviderList getAuxiliaryProviderList()

Return the auxiliary provider list.

bindExpression

ValueNode bindExpression(FromList fromList,
 SubqueryList subqueryList,
 List<AggregateNode> aggregates)
                  throws StandardException

Binding the generation clause.

Overrides:

bindExpression in class ValueNode

Throws:

StandardException

generateExpression

void generateExpression(ExpressionClassBuilder acb,
 MethodBuilder mb)
                 throws StandardException

Generate code for this node.

Overrides:

generateExpression in class ValueNode

Parameters:

acb - The ExpressionClassBuilder for the class being built

mb - The method the code to place the code

Throws:

StandardException - Thrown on error

isEquivalent

boolean isEquivalent(ValueNode other)
              throws StandardException

Description copied from class: ValueNode

Tests if this node is equivalent to the specified ValueNode. Two ValueNodes are considered equivalent if they will evaluate to the same value during query execution.

This method provides basic expression matching facility for the derived class of ValueNode and it is used by the language layer to compare the node structural form of the two expressions for equivalence at bind phase.

Note that it is not comparing the actual row values at runtime to produce a result; hence, when comparing SQL NULLs, they are considered to be equivalent and not unknown.

One usage case of this method in this context is to compare the select column expression against the group by expression to check if they are equivalent. e.g.:

SELECT c1+c2 FROM t1 GROUP BY c1+c2

In general, node equivalence is determined by the derived class of ValueNode. But they generally abide to the rules below:

• The two ValueNodes must be of the same node type to be considered equivalent. e.g.: CastNode vs. CastNode - equivalent (if their args also match), ColumnReference vs CastNode - not equivalent.
• If node P contains other ValueNode(s) and so on, those node(s) must also be of the same node type to be considered equivalent.
• If node P takes a parameter list, then the number of arguments and its arguments for the two nodes must also match to be considered equivalent. e.g.: CAST(c1 as INTEGER) vs CAST(c1 as SMALLINT), they are not equivalent.
• When comparing SQL NULLs in this context, they are considered to be equivalent.
• If this does not apply or it is determined that the two nodes are not equivalent then the derived class of this method should return false; otherwise, return true.

Specified by:

isEquivalent in class ValueNode

Parameters:

other - the node to compare this ValueNode against.

Returns:

true if the two nodes are equivalent, false otherwise.

Throws:

StandardException

findReferencedColumns

public List<ColumnReference> findReferencedColumns()
                                            throws StandardException

Return a list of columns referenced in the generation expression.

Throws:

StandardException - Thrown on error

acceptChildren

void acceptChildren(Visitor v)
             throws StandardException

Accept the visitor for all visitable children of this node.

Overrides:

acceptChildren in class QueryTreeNode

Parameters:

v - the visitor

Throws:

StandardException - on error

toString

public String toString()

Description copied from class: ValueNode

Convert this object to a String. See comments in QueryTreeNode.java for how this should be done for tree printing.

Overrides:

toString in class ValueNode

Returns:

This object as a String

printSubNodes

void printSubNodes(int depth)

Prints the sub-nodes of this object. See QueryTreeNode.java for how tree printing is supposed to work.

Overrides:

printSubNodes in class QueryTreeNode

Parameters:

depth - The depth of this node in the tree