org.apache.derby.impl.sql.compile

Class BooleanConstantNode

java.lang.Object

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

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

org.apache.derby.impl.sql.compile.ConstantNode

org.apache.derby.impl.sql.compile.BooleanConstantNode

All Implemented Interfaces:

Node, Visitable

public final class BooleanConstantNode
extends ConstantNode

Field Summary

Fields

Modifier and Type	Field and Description
(package private) boolean	booleanValue
(package private) boolean	unknownValue

Fields inherited from class org.apache.derby.impl.sql.compile.ConstantNode

value

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

Constructor Summary

Constructors

Constructor and Description
BooleanConstantNode()

Method Summary

Modifier and Type	Method and Description
(package private) ValueNode	eliminateNots(boolean underNotNode) Eliminate NotNodes in the current query block.
(package private) void	generateConstant(ExpressionClassBuilder acb, MethodBuilder mb) This generates the proper constant.
(package private) java.lang.Object	getConstantValueAsObject() Return an Object representing the bind time value of this expression tree.
(package private) java.lang.String	getValueAsString() Return the value as a string.
void	init(java.lang.Object arg1) Initializer for a BooleanConstantNode.
(package private) boolean	isBooleanFalse() Does this represent a false constant.
(package private) boolean	isBooleanTrue() Does this represent a true constant.
double	selectivity(Optimizable optTable) The default selectivity for value nodes is 50%.
void	setValue(DataValueDescriptor value) Set the value in this ConstantNode.

Methods inherited from class org.apache.derby.impl.sql.compile.ConstantNode

bindExpression, constantExpression, generateExpression, getClone, getOrderableVariantType, getValue, init, isCloneable, isConstantExpression, isEquivalent, isNull, toString

Methods inherited from class org.apache.derby.impl.sql.compile.ValueNode

bindExpression, categorize, changeToCNF, checkIsBoolean, checkTopPredicatesForEqualsConditions, copyFields, evaluateConstantExpressions, genEqualsFalseTree, generate, generateFilter, genIsNullTree, genSQLJavaSQLTree, getColumnName, getDataValueFactory, getSchemaName, getSourceResultColumn, getTableName, getTablesReferenced, getTransformed, getTypeCompiler, getTypeId, getTypeServices, init, isBinaryEqualsOperatorNode, isInListProbeNode, isParameterNode, isRelationalOperator, isSameNodeType, optimizableEqualityNode, preprocess, putAndsOnTop, remapColumnReferencesToExpressions, requiresTypeFromContext, 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, bindUserCatalogType, 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, getSchemaDescriptor, getSchemaDescriptor, getStatementType, getTableDescriptor, getTypeCompiler, init, init, init, init, init, init, init, init, init, init, init, isAtomic, isInstanceOf, isPrivilegeCollectionRequired, isSessionSchema, isSessionSchema, makeConstantAction, makeTableName, makeTableName, nodeHeader, orReliability, parseStatement, printLabel, printSubNodes, 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

booleanValue

boolean booleanValue

unknownValue

boolean unknownValue

Constructor Detail

BooleanConstantNode

public BooleanConstantNode()

Method Detail

init

public void init(java.lang.Object arg1)
          throws StandardException

Initializer for a BooleanConstantNode.

Specified by:

init in interface Node

Overrides:

init in class QueryTreeNode

Parameters:

arg1 - A boolean containing the value of the constant OR The TypeId for the type of the node

Throws:

StandardException

getConstantValueAsObject

java.lang.Object getConstantValueAsObject()

Return an Object representing the bind time value of this expression tree. If the expression tree does not evaluate to a constant at bind time then we return null. This is useful for bind time resolution of VTIs. RESOLVE: What do we do for primitives?

Overrides:

getConstantValueAsObject in class ValueNode

Returns:

An Object representing the bind time value of this expression tree. (null if not a bind time constant.)

getValueAsString

java.lang.String getValueAsString()

Return the value as a string.

Returns:

The value as a string.

isBooleanTrue

boolean isBooleanTrue()

Does this represent a true constant.

Overrides:

isBooleanTrue in class ValueNode

Returns:

Whether or not this node represents a true constant.

isBooleanFalse

boolean isBooleanFalse()

Does this represent a false constant.

Overrides:

isBooleanFalse in class ValueNode

Returns:

Whether or not this node represents a false constant.

selectivity

public double selectivity(Optimizable optTable)

The default selectivity for value nodes is 50%. This is overridden in specific cases, such as the RelationalOperators.

Overrides:

selectivity in class ValueNode

eliminateNots

ValueNode eliminateNots(boolean underNotNode)

Eliminate NotNodes in the current query block. We traverse the tree, inverting ANDs and ORs and eliminating NOTs as we go. We stop at ComparisonOperators and boolean expressions. We invert ComparisonOperators and replace boolean expressions with boolean expression = false. NOTE: Since we do not recurse under ComparisonOperators, there still could be NotNodes left in the tree.

Overrides:

eliminateNots in class ValueNode

Parameters:

underNotNode - Whether or not we are under a NotNode.

Returns:

The modified expression

generateConstant

void generateConstant(ExpressionClassBuilder acb,
                      MethodBuilder mb)

This generates the proper constant. It is implemented by every specific constant node (e.g. IntConstantNode).

Specified by:

generateConstant in class ConstantNode

Parameters:

acb - The ExpressionClassBuilder for the class being built

mb - The method the code to place the code

setValue

public void setValue(DataValueDescriptor value)

Set the value in this ConstantNode.

Overrides:

setValue in class ConstantNode