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

java.lang.Object
  org.apache.derby.impl.sql.compile.QueryTreeNode
      org.apache.derby.impl.sql.compile.ValueNode
          org.apache.derby.impl.sql.compile.BinaryOperatorNode
              org.apache.derby.impl.sql.compile.BinaryLogicalOperatorNode
                  org.apache.derby.impl.sql.compile.OrNode

All Implemented Interfaces:

Visitable

public class OrNode
extends BinaryLogicalOperatorNode

Field Summary

private boolean

firstOr

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

shortCircuitValue

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

AND, BinaryArgTypes, BinaryMethodNames, BinaryOperators, BinaryResultTypes, CONCATENATE, DIVIDE, EQ, GE, GT, LE, leftInterfaceType, leftOperand, LIKE, LT, methodName, MINUS, NE, operator, operatorType, OR, PLUS, receiver, resultInterfaceType, rightInterfaceType, rightOperand, TIMES, XMLEXISTS_OP, XMLQUERY_OP

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

OrNode()

Method Summary

ValueNode	bindExpression(FromList fromList, SubqueryList subqueryList, java.util.Vector aggregateVector) Bind this logical operator.
ValueNode	changeToCNF(boolean underTopAndNode) Finish putting an expression into conjunctive normal form.
(package private) ValueNode	eliminateNots(boolean underNotNode) Eliminate NotNodes in the current query block.
void	init(java.lang.Object leftOperand, java.lang.Object rightOperand) Initializer for an OrNode
(package private) void	postBindFixup() Do bind() by hand for an AndNode that was generated after bind(), eg by putAndsOnTop().
ValueNode	preprocess(int numTables, FromList outerFromList, SubqueryList outerSubqueryList, PredicateList outerPredicateList) Preprocess an expression tree.
(package private) void	setFirstOr() Mark this OrNode as the 1st OR in the OR chain.
boolean	verifyChangeToCNF() Verify that changeToCNF() did its job correctly.

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

generateExpression, init, resolveLogicalBinaryOperator, verifyEliminateNots

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

acceptChildren, bindXMLQuery, categorize, constantExpression, genSQLJavaSQLTree, getLeftOperand, getOrderableVariantType, getReceiverInterfaceName, getRightOperand, init, init, initializeResultField, isConstantExpression, isEquivalent, printSubNodes, remapColumnReferencesToExpressions, setLeftOperand, setLeftRightInterfaceType, setMethodName, setOperator, setRightOperand, toString

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

bindExpression, checkIsBoolean, checkTopPredicatesForEqualsConditions, copyFields, evaluateConstantExpressions, genEqualsFalseTree, generate, generateFilter, genIsNullTree, getClone, getColumnName, getConstantValueAsObject, getDataValueFactory, getSchemaName, getSourceResultColumn, getTableName, getTablesReferenced, getTransformed, getTypeCompiler, getTypeId, getTypeServices, init, isBinaryEqualsOperatorNode, isBooleanFalse, isBooleanTrue, isCloneable, isInListProbeNode, isParameterNode, isRelationalOperator, isSameNodeType, optimizableEqualityNode, putAndsOnTop, requiresTypeFromContext, selectivity, setCollationInfo, setCollationInfo, setCollationUsingCompilationSchema, setCollationUsingCompilationSchema, setNullability, setTransformed, setType, setType, setType, updatableByCursor, verifyPutAndsOnTop

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

accept, 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, 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

firstOr

private boolean firstOr

Constructor Detail

OrNode

public OrNode()

Method Detail

init

public void init(java.lang.Object leftOperand,
                 java.lang.Object rightOperand)

Initializer for an OrNode

Overrides:

init in class QueryTreeNode

Parameters:

leftOperand - The left operand of the OR

rightOperand - The right operand of the OR

setFirstOr

void setFirstOr()

Mark this OrNode as the 1st OR in the OR chain. We will consider converting the chain to an IN list during preprocess() if all entries are of the form: ColumnReference = expression

bindExpression

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

Bind this logical operator. All that has to be done for binding a logical operator is to bind the operands, check that both operands are BooleanDataValue, and set the result type to BooleanDataValue.

Overrides:

bindExpression in class BinaryLogicalOperatorNode

Parameters:

fromList - The query's FROM list

subqueryList - The subquery list being built as we find SubqueryNodes

aggregateVector - The aggregate vector being built as we find AggregateNodes

Returns:

The new top of the expression tree.

Throws:

StandardException - Thrown on error

preprocess

public ValueNode preprocess(int numTables,
                            FromList outerFromList,
                            SubqueryList outerSubqueryList,
                            PredicateList outerPredicateList)
                     throws StandardException

Preprocess an expression tree. We do a number of transformations here (including subqueries, IN lists, LIKE and BETWEEN) plus subquery flattening. NOTE: This is done before the outer ResultSetNode is preprocessed.

Overrides:

preprocess in class BinaryOperatorNode

Parameters:

numTables - Number of tables in the DML Statement

outerFromList - FromList from outer query block

outerSubqueryList - SubqueryList from outer query block

outerPredicateList - PredicateList from outer query block

Returns:

The modified expression

Throws:

StandardException - Thrown on error

eliminateNots

ValueNode eliminateNots(boolean underNotNode)
                  throws StandardException

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

Throws:

StandardException - Thrown on error

changeToCNF

public ValueNode changeToCNF(boolean underTopAndNode)
                      throws StandardException

Finish putting an expression into conjunctive normal form. An expression tree in conjunctive normal form meets the following criteria: o If the expression tree is not null, the top level will be a chain of AndNodes terminating in a true BooleanConstantNode. o The left child of an AndNode will never be an AndNode. o Any right-linked chain that includes an AndNode will be entirely composed of AndNodes terminated by a true BooleanConstantNode. o The left child of an OrNode will never be an OrNode. o Any right-linked chain that includes an OrNode will be entirely composed of OrNodes terminated by a false BooleanConstantNode. o ValueNodes other than AndNodes and OrNodes are considered leaf nodes for purposes of expression normalization. In other words, we won't do any normalization under those nodes. In addition, we track whether or not we are under a top level AndNode. SubqueryNodes need to know this for subquery flattening.

Overrides:

changeToCNF in class ValueNode

Parameters:

underTopAndNode - Whether or not we are under a top level AndNode.

Returns:

The modified expression

Throws:

StandardException - Thrown on error

verifyChangeToCNF

public boolean verifyChangeToCNF()

Verify that changeToCNF() did its job correctly. Verify that: o AndNode - rightOperand is not instanceof OrNode leftOperand is not instanceof AndNode o OrNode - rightOperand is not instanceof AndNode leftOperand is not instanceof OrNode

Overrides:

verifyChangeToCNF in class ValueNode

Returns:

Boolean which reflects validity of the tree.

postBindFixup

void postBindFixup()
             throws StandardException

Do bind() by hand for an AndNode that was generated after bind(), eg by putAndsOnTop(). (Set the data type and nullability info.)

Throws:

StandardException - Thrown on error