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

java.lang.Object
  extended by org.apache.derby.impl.sql.compile.QueryTreeNode
      extended by org.apache.derby.impl.sql.compile.ValueNode
          extended by org.apache.derby.impl.sql.compile.GenerationClauseNode
All Implemented Interfaces:
Visitable

public class GenerationClauseNode
extends ValueNode

This node describes a Generation Clause in a column definition.


Field Summary
private  ProviderList _apl
           
private  ValueNode _boundExpression
           
private  java.lang.String _expressionText
           
private  ValueNode _generationExpression
           
 
Fields inherited from class org.apache.derby.impl.sql.compile.ValueNode
transformed
 
Fields inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode
AUTOINCREMENT_CREATE_MODIFY, AUTOINCREMENT_INC_INDEX, AUTOINCREMENT_IS_AUTOINCREMENT_INDEX, AUTOINCREMENT_START_INDEX, isPrivilegeCollectionRequired
 
Constructor Summary
GenerationClauseNode()
           
 
Method Summary
 ValueNode bindExpression(FromList fromList, SubqueryList subqueryList, java.util.Vector aggregateVector)
          Binding the generation clause.
 java.util.Vector findReferencedColumns()
          Return a vector of columns referenced in the generation expression.
 void generateExpression(ExpressionClassBuilder acb, MethodBuilder mb)
          Generate code for this node.
 ProviderList getAuxiliaryProviderList()
          Return the auxiliary provider list.
 java.lang.String getExpressionText()
          Get the defining text of this generation clause
 void init(java.lang.Object generationExpression, java.lang.Object expressionText)
          Initialize a query tree node.
protected  boolean isEquivalent(ValueNode other)
          Tests if this node is equivalent to the specified ValueNode.
 void printSubNodes(int depth)
          Prints the sub-nodes of this object.
(package private)  void setAuxiliaryProviderList(ProviderList apl)
          Set the auxiliary provider list.
 java.lang.String toString()
          Convert this object to a String.
 
Methods inherited from class org.apache.derby.impl.sql.compile.ValueNode
bindExpression, categorize, changeToCNF, checkIsBoolean, checkTopPredicatesForEqualsConditions, constantExpression, copyFields, eliminateNots, evaluateConstantExpressions, genEqualsFalseTree, generate, generateFilter, genIsNullTree, genSQLJavaSQLTree, getClone, getColumnName, getConstantValueAsObject, getDataValueFactory, getOrderableVariantType, getSchemaName, getSourceResultColumn, getTableName, getTablesReferenced, getTransformed, getTypeCompiler, getTypeId, getTypeServices, init, isBinaryEqualsOperatorNode, isBooleanFalse, isBooleanTrue, isCloneable, isConstantExpression, isInListProbeNode, isParameterNode, isRelationalOperator, isSameNodeType, optimizableEqualityNode, preprocess, putAndsOnTop, remapColumnReferencesToExpressions, requiresTypeFromContext, selectivity, setCollationInfo, setCollationInfo, setCollationUsingCompilationSchema, setCollationUsingCompilationSchema, setNullability, setTransformed, setType, setType, setType, updatableByCursor, verifyChangeToCNF, verifyEliminateNots, verifyPutAndsOnTop
 
Methods inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode
accept, acceptChildren, bindOffsetFetch, bindRowMultiSet, bindUserType, checkReliability, checkReliability, convertDefaultNode, createTypeDependency, debugFlush, debugPrint, disablePrivilegeCollection, formatNodeString, foundString, generateAuthorizeCheck, getBeginOffset, getClassFactory, getCompilerContext, getContextManager, getCursorInfo, getDataDictionary, getDependencyManager, getEndOffset, getExecutionFactory, getGenericConstantActionFactory, getIntProperty, getLanguageConnectionContext, getNodeFactory, getNodeType, getNullNode, getParameterTypes, getRowEstimate, getSchemaDescriptor, getSchemaDescriptor, getStatementType, getTableDescriptor, getTypeCompiler, init, init, init, init, init, init, init, init, init, init, init, init, isAtomic, isInstanceOf, isPrivilegeCollectionRequired, isSessionSchema, isSessionSchema, makeConstantAction, makeTableName, makeTableName, nodeHeader, orReliability, parseStatement, printLabel, referencesSessionSchema, resolveTableToSynonym, setBeginOffset, setContextManager, setEndOffset, setNodeType, setRefActionInfo, stackPrint, treePrint, treePrint, verifyClassExist
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

_generationExpression

private ValueNode _generationExpression

_expressionText

private java.lang.String _expressionText

_boundExpression

private ValueNode _boundExpression

_apl

private ProviderList _apl
Constructor Detail

GenerationClauseNode

public GenerationClauseNode()
Method Detail

init

public void init(java.lang.Object generationExpression,
                 java.lang.Object expressionText)
Description copied from class: QueryTreeNode
Initialize a query tree node.

Overrides:
init in class QueryTreeNode

getExpressionText

public java.lang.String getExpressionText()
Get the defining text of this generation clause


setAuxiliaryProviderList

void setAuxiliaryProviderList(ProviderList apl)
Set the auxiliary provider list.


getAuxiliaryProviderList

public ProviderList getAuxiliaryProviderList()
Return the auxiliary provider list.


bindExpression

public ValueNode bindExpression(FromList fromList,
                                SubqueryList subqueryList,
                                java.util.Vector aggregateVector)
                         throws StandardException
Binding the generation clause.

Overrides:
bindExpression in class ValueNode
Throws:
StandardException

generateExpression

public 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

protected 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:

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 java.util.Vector findReferencedColumns()
                                       throws StandardException
Return a vector of columns referenced in the generation expression.

Throws:
StandardException - Thrown on error

toString

public java.lang.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

public 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

Built on Thu 2012-03-29 21:53:33+0000, from revision ???

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