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

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

All Implemented Interfaces:

Node, Visitable

public class AggregateNode
extends UnaryOperatorNode

An Aggregate Node is a node that reprsents a set function/aggregate. It used for all system aggregates as well as user defined aggregates.

Field Summary

private java.lang.Class	aggregateDefinitionClass
private java.lang.String	aggregateDefinitionClassName
private java.lang.String	aggregateName
private java.lang.StringBuffer	aggregatorClassName
private ClassInspector	classInspector
private boolean	distinct
private ResultColumn	generatedRC
private ColumnReference	generatedRef
private AggregateDefinition	uad
private TableName	userAggregateName

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

methodName, operand, operator, receiverInterfaceType, resultInterfaceType, UnaryArgTypes, UnaryMethodNames, UnaryOperators, UnaryResultTypes, XMLPARSE_OP, XMLSERIALIZE_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

AggregateNode()

Method Summary

ValueNode	bindExpression(FromList fromList, SubqueryList subqueryList, java.util.List aggregateVector) Bind this operator.
private void	checkAggregatorClassName(java.lang.String className)
boolean	constantExpression(PredicateList where) Return whether or not this expression tree represents a constant value.
void	generateExpression(ExpressionClassBuilder acb, MethodBuilder mb) Do code generation for this unary operator.
(package private) AggregateDefinition	getAggregateDefinition() Get the AggregateDefinition.
java.lang.String	getAggregateName() Get the class that implements that aggregator for this node.
java.lang.String	getAggregatorClassName() Get the class that implements that aggregator for this node.
ResultColumn	getGeneratedRC() Get the generated ResultColumn where this aggregate now resides after a call to replaceAggregatesWithColumnReference().
ColumnReference	getGeneratedRef() Get the generated ColumnReference to this aggregate after the parent called replaceAggregatesWithColumnReference().
ResultColumn	getNewAggregatorResultColumn(DataDictionary dd) Get the result column that has a new aggregator.
ResultColumn	getNewExpressionResultColumn(DataDictionary dd) Get the aggregate expression in a new result column.
ValueNode	getNewNullResultExpression() Get the null aggregate result expression column.
java.lang.String	getSQLName() Get the SQL name of the aggregate
void	init(java.lang.Object operand, java.lang.Object uadClass, java.lang.Object distinct, java.lang.Object aggregateName) Intializer.
private void	instantiateAggDef()
boolean	isConstant()
boolean	isDistinct() Indicate whether this aggregate is distinct or not.
private boolean	isUserDefinedAggregate() Return true if this is a user-defined aggregate
ValueNode	replaceAggregatesWithColumnReferences(ResultColumnList rcl, int tableNumber) Replace aggregates in the expression tree with a ColumnReference to that aggregate, append the aggregate to the supplied RCL (assumed to be from the child ResultSetNode) and return the ColumnReference.
static AliasDescriptor	resolveAggregate(DataDictionary dd, SchemaDescriptor sd, java.lang.String rawName) Resolve a user-defined aggregate.
private void	setUserDefinedAggregate(UserAggregateDefinition userAgg) initialize fields for user defined aggregate
java.lang.String	toString() Print a string ref of this node.

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

acceptChildren, addXmlOpMethodParams, bindOperand, bindParameter, categorize, getOperand, getOperatorString, getOrderableVariantType, getParameterOperand, getReceiverInterfaceName, init, init, isConstantExpression, isEquivalent, preprocess, printSubNodes, remapColumnReferencesToExpressions, setMethodName, setOperator

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

pushSqlXmlUtil

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

bindExpression, changeToCNF, checkIsBoolean, checkTopPredicatesForEqualsConditions, copyFields, eliminateNots, evaluateConstantExpressions, genEqualsFalseTree, generate, generateFilter, genIsNullTree, genSQLJavaSQLTree, 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, verifyChangeToCNF, verifyEliminateNots, verifyPutAndsOnTop

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

accept, 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, 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

distinct

private boolean distinct

uad

private AggregateDefinition uad

userAggregateName

private TableName userAggregateName

aggregatorClassName

private java.lang.StringBuffer aggregatorClassName

aggregateDefinitionClassName

private java.lang.String aggregateDefinitionClassName

aggregateDefinitionClass

private java.lang.Class aggregateDefinitionClass

classInspector

private ClassInspector classInspector

aggregateName

private java.lang.String aggregateName

generatedRC

private ResultColumn generatedRC

generatedRef

private ColumnReference generatedRef

Constructor Detail

AggregateNode

public AggregateNode()

Method Detail

init

public void init(java.lang.Object operand,
                 java.lang.Object uadClass,
                 java.lang.Object distinct,
                 java.lang.Object aggregateName)
          throws StandardException

Intializer. Used for user defined and internally defined aggregates. Called when binding a StaticMethodNode that we realize is an aggregate.

Specified by:

init in interface Node

Overrides:

init in class QueryTreeNode

Parameters:

operand - the value expression for the aggregate

uadClass - the class name for user aggregate definition for the aggregate or the Class for the internal aggregate type.

distinct - boolean indicating whether this is distinct or not.

aggregateName - the name of the aggregate from the user's perspective, e.g. MAX

Throws:

StandardException - on error

setUserDefinedAggregate

private void setUserDefinedAggregate(UserAggregateDefinition userAgg)

initialize fields for user defined aggregate

replaceAggregatesWithColumnReferences

public ValueNode replaceAggregatesWithColumnReferences(ResultColumnList rcl,
                                                       int tableNumber)
                                                throws StandardException

Replace aggregates in the expression tree with a ColumnReference to that aggregate, append the aggregate to the supplied RCL (assumed to be from the child ResultSetNode) and return the ColumnReference. This is useful for pushing aggregates in the Having clause down to the user's select at parse time. It is also used for moving around Aggregates in the select list when creating the Group By node. In that case it is called after bind time, so we need to create the column differently.

Parameters:

rcl - The RCL to append to.

tableNumber - The tableNumber for the new ColumnReference

Returns:

ValueNode The (potentially) modified tree.

Throws:

StandardException - Thrown on error

getAggregateDefinition

AggregateDefinition getAggregateDefinition()

Get the AggregateDefinition.

Returns:

The AggregateDefinition

getGeneratedRC

public ResultColumn getGeneratedRC()

Get the generated ResultColumn where this aggregate now resides after a call to replaceAggregatesWithColumnReference().

Returns:

the result column

getGeneratedRef

public ColumnReference getGeneratedRef()

Get the generated ColumnReference to this aggregate after the parent called replaceAggregatesWithColumnReference().

Returns:

the column reference

bindExpression

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

Bind this operator. Determine the type of the subexpression, and pass that into the UserAggregate.

Overrides:

bindExpression in class UnaryOperatorNode

Parameters:

fromList - The query's FROM list

subqueryList - The subquery list being built as we find SubqueryNodes

aggregateVector - The aggregate list being built as we find AggregateNodes

Returns:

The new top of the expression tree.

Throws:

StandardException - Thrown on error

resolveAggregate

public static AliasDescriptor resolveAggregate(DataDictionary dd,
                                               SchemaDescriptor sd,
                                               java.lang.String rawName)
                                        throws StandardException

Resolve a user-defined aggregate.

Throws:

StandardException

checkAggregatorClassName

private void checkAggregatorClassName(java.lang.String className)
                               throws StandardException

Throws:

StandardException

instantiateAggDef

private void instantiateAggDef()
                        throws StandardException

Throws:

StandardException

isDistinct

public boolean isDistinct()

Indicate whether this aggregate is distinct or not.

Returns:

true/false

getAggregatorClassName

public java.lang.String getAggregatorClassName()

Get the class that implements that aggregator for this node.

Returns:

the class name

getAggregateName

public java.lang.String getAggregateName()

Get the class that implements that aggregator for this node.

Returns:

the class name

getNewAggregatorResultColumn

public ResultColumn getNewAggregatorResultColumn(DataDictionary dd)
                                          throws StandardException

Get the result column that has a new aggregator. This aggregator will be fed into the sorter.

Parameters:

dd - the data dictionary

Returns:

the result column. WARNING: it still needs to be bound

Throws:

StandardException - on error

getNewExpressionResultColumn

public ResultColumn getNewExpressionResultColumn(DataDictionary dd)
                                          throws StandardException

Get the aggregate expression in a new result column.

Parameters:

dd - the data dictionary

Returns:

the result column. WARNING: it still needs to be bound

Throws:

StandardException - on error

getNewNullResultExpression

public ValueNode getNewNullResultExpression()
                                     throws StandardException

Get the null aggregate result expression column.

Returns:

the value node

Throws:

StandardException - on error

generateExpression

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

Do code generation for this unary operator. Should never be called for an aggregate -- it should be converted into something else by code generation time.

Overrides:

generateExpression in class UnaryOperatorNode

Parameters:

acb - The ExpressionClassBuilder for the class we're generating

mb - The method the code to place the code

Throws:

StandardException - Thrown on error

toString

public java.lang.String toString()

Print a string ref of this node.

Overrides:

toString in class UnaryOperatorNode

Returns:

a string representation of this node

isConstant

public boolean isConstant()

constantExpression

public boolean constantExpression(PredicateList where)

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 UnaryOperatorNode

Returns:

True means this expression tree represents a constant value.

See Also:

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

getSQLName

public java.lang.String getSQLName()

Get the SQL name of the aggregate

isUserDefinedAggregate

private boolean isUserDefinedAggregate()

Return true if this is a user-defined aggregate