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

java.lang.Object
  org.apache.derby.impl.sql.compile.QueryTreeNode
      org.apache.derby.impl.sql.compile.ValueNode
          org.apache.derby.impl.sql.compile.UnaryOperatorNode

All Implemented Interfaces:

Visitable

Direct Known Subclasses:

AggregateNode, DB2LengthOperatorNode, ExtractOperatorNode, LengthOperatorNode, QuantifiedUnaryOperatorNode, SimpleStringOperatorNode, UnaryArithmeticOperatorNode, UnaryComparisonOperatorNode, UnaryDateTimestampOperatorNode, UnaryLogicalOperatorNode

public class UnaryOperatorNode

extends ValueNode

A UnaryOperatorNode represents a built-in unary operator as defined by the ANSI/ISO SQL standard. This covers operators like +, -, NOT, and IS NULL. Java operators are not represented here: the JSQL language allows Java methods to be called from expressions, but not Java operators.

Author:

Jeff Lichtman

Field Summary

private java.lang.Object[]	additionalArgs
static int	IS_NULL
(package private) java.lang.String	methodName
static int	NOT
(package private) ValueNode	operand WARNING: operand may be NULL for COUNT(*).
(package private) java.lang.String	operator
(package private) int	operatorType
(package private) java.lang.String	receiverInterfaceType
(package private) java.lang.String	resultInterfaceType
static int	UNARY_MINUS
static int	UNARY_PLUS
(package private) static java.lang.String[]	UnaryArgTypes
(package private) static java.lang.String[]	UnaryMethodNames
(package private) static java.lang.String[]	UnaryOperators
(package private) static java.lang.String[]	UnaryResultTypes
static int	XMLPARSE_OP
static int	XMLSERIALIZE_OP

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

clause, dataTypeServices, IN_HAVING_CLAUSE, IN_SELECT_LIST, IN_UNKNOWN_CLAUSE, IN_WHERE_CLAUSE, transformed

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

AUTOINCREMENT_INC_INDEX, AUTOINCREMENT_IS_AUTOINCREMENT_INDEX, AUTOINCREMENT_START_INDEX, beginOffset, endOffset

Constructor Summary

UnaryOperatorNode()

Method Summary

Visitable	accept(Visitor v) Accept a visitor, and call v.visit() on child nodes as necessary.
protected int	addMethodParams(MethodBuilder mb) This method allows different operators to add primitive arguments to the generated method call, if needed.
ValueNode	bindExpression(FromList fromList, SubqueryList subqueryList, java.util.Vector aggregateVector) Bind this expression.
(package private) void	bindParameter() By default unary operators don't accept ?
protected ValueNode	bindUnaryOperator(FromList fromList, SubqueryList subqueryList, java.util.Vector aggregateVector) Workhorse for bindExpression.
void	bindXMLParse() Bind an XMLPARSE operator.
void	bindXMLSerialize() Bind an XMLSERIALIZE operator.
boolean	categorize(JBitSet referencedTabs, boolean simplePredsOnly) Categorize this predicate.
boolean	constantExpression(PredicateList whereClause) Return whether or not this expression tree represents a constant value.
void	generateExpression(ExpressionClassBuilder acb, MethodBuilder mb) Do code generation for this unary operator.
ValueNode	getOperand() Get the operand of this unary operator.
(package private) java.lang.String	getOperatorString() Get the operator of this unary operator.
protected int	getOrderableVariantType() Return the variant type for the underlying expression.
java.lang.String	getReceiverInterfaceName() Determine the type the binary method is called on.
void	init(java.lang.Object operand) Initializer for a UnaryOperatorNode
void	init(java.lang.Object operand, java.lang.Object operatorOrOpType, java.lang.Object methodNameOrAddedArgs) Initializer for a UnaryOperatorNode
boolean	isConstantExpression() Return whether or not this expression tree represents a constant expression.
ValueNode	preprocess(int numTables, FromList outerFromList, SubqueryList outerSubqueryList, PredicateList outerPredicateList) Preprocess an expression tree.
void	printSubNodes(int depth) Prints the sub-nodes of this object.
ValueNode	remapColumnReferencesToExpressions() Remap all ColumnReferences in this tree to be clones of the underlying expression.
void	setClause(int clause) Set the clause that this node appears in.
(package private) void	setMethodName(java.lang.String methodName) Set the methodName.
(package private) void	setOperator(java.lang.String operator) Set the operator.
java.lang.String	toString() Convert this object to a String.

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

bindExpression, changeToCNF, checkIsBoolean, checkReliability, checkReliability, checkTopPredicatesForEqualsConditions, copyFields, eliminateNots, genEqualsFalseTree, generate, generateFilter, genIsNullTree, genSQLJavaSQLTree, getClause, getClone, getColumnName, getConstantValueAsObject, getDataValueFactory, getSchemaName, getSourceResultColumn, getTableName, getTablesReferenced, getTransformed, getTypeCompiler, getTypeId, getTypeServices, init, isBinaryEqualsOperatorNode, isBooleanFalse, isBooleanTrue, isCloneable, isParameterNode, isRelationalOperator, optimizableEqualityNode, putAndsOnTop, selectivity, setDescriptor, setTransformed, setType, updatableByCursor, verifyChangeToCNF, verifyEliminateNots, verifyPutAndsOnTop

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

bind, convertDefaultNode, debugFlush, debugPrint, executeSchemaName, executeStatementName, formatNodeString, foundString, generate, generateAuthorizeCheck, getBeginOffset, getClassFactory, getCompilerContext, getContextManager, getCursorInfo, getDataDictionary, getDependencyManager, getEndOffset, getExecutionFactory, getGenericConstantActionFactory, getIntProperty, getLanguageConnectionContext, getNodeFactory, getNodeType, getNullNode, getParameterTypes, getRowEstimate, getSchemaDescriptor, getSchemaDescriptor, getSPSName, getStatementType, getTableDescriptor, getTypeCompiler, init, init, init, init, init, init, init, init, init, init, init, isAtomic, isInstanceOf, isSessionSchema, isSessionSchema, makeConstantAction, makeResultDescription, makeTableName, needsSavepoint, nodeHeader, optimize, parseQueryText, printLabel, referencesSessionSchema, resolveTableToSynonym, setBeginOffset, setContextManager, setEndOffset, setNodeType, setRefActionInfo, treePrint, treePrint, verifyClassExist

Methods inherited from class java.lang.Object

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

Field Detail

operator

java.lang.String operator

methodName

java.lang.String methodName

operatorType

int operatorType

resultInterfaceType

java.lang.String resultInterfaceType

receiverInterfaceType

java.lang.String receiverInterfaceType

operand

ValueNode operand

WARNING: operand may be NULL for COUNT(*).

UNARY_PLUS

public static final int UNARY_PLUS

See Also:

Constant Field Values

UNARY_MINUS

public static final int UNARY_MINUS

See Also:

Constant Field Values

NOT

public static final int NOT

See Also:

Constant Field Values

IS_NULL

public static final int IS_NULL

See Also:

Constant Field Values

XMLPARSE_OP

public static final int XMLPARSE_OP

See Also:

Constant Field Values

XMLSERIALIZE_OP

public static final int XMLSERIALIZE_OP

See Also:

Constant Field Values

UnaryOperators

static final java.lang.String[] UnaryOperators

UnaryMethodNames

static final java.lang.String[] UnaryMethodNames

UnaryResultTypes

static final java.lang.String[] UnaryResultTypes

UnaryArgTypes

static final java.lang.String[] UnaryArgTypes

additionalArgs

private java.lang.Object[] additionalArgs

Constructor Detail

UnaryOperatorNode

public UnaryOperatorNode()

Method Detail

init

public void init(java.lang.Object operand,
                 java.lang.Object operatorOrOpType,
                 java.lang.Object methodNameOrAddedArgs)

Initializer for a UnaryOperatorNode

Overrides:

init in class QueryTreeNode

Parameters:

operand - The operand of the node

operatorOrOpType - Either 1) the name of the operator, OR 2) an Integer holding the operatorType for this operator.

init

public void init(java.lang.Object operand)

Initializer for a UnaryOperatorNode

Overrides:

init in class QueryTreeNode

Parameters:

operand - The operand of the node

setOperator

void setOperator(java.lang.String operator)

Set the operator.

Parameters:

operator - The operator.

Returns:

Nothing.

getOperatorString

java.lang.String getOperatorString()

Get the operator of this unary operator.

Returns:

The operator of this unary operator.

setMethodName

void setMethodName(java.lang.String methodName)

Set the methodName.

Parameters:

methodName - The methodName.

Returns:

Nothing.

toString

public java.lang.String toString()

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

Returns:

Nothing

getOperand

public ValueNode getOperand()

Get the operand of this unary operator.

Returns:

The operand of this unary operator.

setClause

public void setClause(int clause)

Set the clause that this node appears in.

Overrides:

setClause in class ValueNode

Parameters:

clause - The clause that this node appears in.

Returns:

Nothing.

bindExpression

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

Bind this expression. This means binding the sub-expressions, as well as figuring out what the return type is for this expression.

Overrides:

bindExpression in class ValueNode

Parameters:

fromList - The FROM list for the query this expression is in, for binding columns.

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

bindUnaryOperator

protected ValueNode bindUnaryOperator(FromList fromList,
                                      SubqueryList subqueryList,
                                      java.util.Vector aggregateVector)
                               throws StandardException

Workhorse for bindExpression. This exists so it can be called by child classes.

Throws:

StandardException

bindXMLParse

public void bindXMLParse()
                  throws StandardException

Bind an XMLPARSE operator. Makes sure the operand type is correct, and sets the result type.

Throws:

StandardException - Thrown on error

bindXMLSerialize

public void bindXMLSerialize()
                      throws StandardException

Bind an XMLSERIALIZE operator. Makes sure the operand type and target type are both correct, and sets the result type.

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 ValueNode

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

categorize

public boolean categorize(JBitSet referencedTabs,
                          boolean simplePredsOnly)
                   throws StandardException

Categorize this predicate. Initially, this means building a bit map of the referenced tables for each predicate. If the source of this ColumnReference (at the next underlying level) is not a ColumnReference or a VirtualColumnNode then this predicate will not be pushed down. For example, in: select * from (select 1 from s) a (x) where x = 1 we will not push down x = 1. NOTE: It would be easy to handle the case of a constant, but if the inner SELECT returns an arbitrary expression, then we would have to copy that tree into the pushed predicate, and that tree could contain subqueries and method calls. RESOLVE - revisit this issue once we have views.

Overrides:

categorize in class ValueNode

Parameters:

referencedTabs - JBitSet with bit map of referenced FromTables

simplePredsOnly - Whether or not to consider method calls, field references and conditional nodes when building bit map

Returns:

boolean Whether or not source.expression is a ColumnReference or a VirtualColumnNode.

Throws:

StandardException - Thrown on error

remapColumnReferencesToExpressions

public ValueNode remapColumnReferencesToExpressions()
                                             throws StandardException

Remap all ColumnReferences in this tree to be clones of the underlying expression.

Overrides:

remapColumnReferencesToExpressions in class ValueNode

Returns:

ValueNode The remapped expression tree.

Throws:

StandardException - Thrown on error

isConstantExpression

public boolean isConstantExpression()

Return whether or not this expression tree represents a constant expression.

Overrides:

isConstantExpression in class ValueNode

Returns:

Whether or not this expression tree represents a constant expression.

constantExpression

public boolean constantExpression(PredicateList whereClause)

Description copied from class: ValueNode

Return whether or not this expression tree represents a constant value. In this case, "constant" means that it will always evaluate to the same thing, even if it includes columns. A column is constant if it is compared to a constant expression.

Overrides:

constantExpression in class ValueNode

Returns:

True means this expression tree represents a constant value.

See Also:

ValueNode.constantExpression(org.apache.derby.impl.sql.compile.PredicateList)

bindParameter

void bindParameter()
             throws StandardException

By default unary operators don't accept ? parameters as operands. This can be over-ridden for particular unary operators. We throw an exception if the parameter doesn't have a datatype assigned to it yet.

Returns:

Nothing

Throws:

StandardException - Thrown if ? parameter doesn't have a type bound to it yet. ? parameter where it isn't allowed.

generateExpression

public void generateExpression(ExpressionClassBuilder acb,
                               MethodBuilder mb)
                        throws StandardException

Do code generation for this unary operator.

Overrides:

generateExpression in class ValueNode

Parameters:

acb - The ExpressionClassBuilder for the class we're generating

mb - The method the expression will go into

Throws:

StandardException - Thrown on error

getReceiverInterfaceName

public java.lang.String getReceiverInterfaceName()
                                          throws StandardException

Determine the type the binary method is called on. By default, based on the receiver. Override in nodes that use methods on super-interfaces of the receiver's interface, such as comparisons.

Throws:

StandardException - Thrown on error

getOrderableVariantType

protected int getOrderableVariantType()
                               throws StandardException

Return the variant type for the underlying expression. The variant type can be: VARIANT - variant within a scan (method calls and non-static field access) SCAN_INVARIANT - invariant within a scan (column references from outer tables) QUERY_INVARIANT - invariant within the life of a query (constant expressions) CONSTANT - immutable

Overrides:

getOrderableVariantType in class ValueNode

Returns:

The variant type for the underlying expression.

Throws:

StandardException - thrown on error

accept

public Visitable accept(Visitor v)
                 throws StandardException

Accept a visitor, and call v.visit() on child nodes as necessary.

Specified by:

accept in interface Visitable

Overrides:

accept in class QueryTreeNode

Parameters:

v - the visitor

Throws:

StandardException - on error

addMethodParams

protected int addMethodParams(MethodBuilder mb)

This method allows different operators to add primitive arguments to the generated method call, if needed.

Parameters:

mb - The MethodBuilder that will make the call.

Returns:

Number of parameters added.