Package org.h2.expression.aggregate

Class Aggregate

java.lang.Object

org.h2.expression.Expression

org.h2.expression.analysis.DataAnalysisOperation

org.h2.expression.aggregate.AbstractAggregate

org.h2.expression.aggregate.Aggregate

All Implemented Interfaces:

ExpressionWithFlags, HasSQL, Typed

public class Aggregate
extends AbstractAggregate
implements ExpressionWithFlags

Implements the integrated aggregate functions, such as COUNT, MAX, SUM.

Field Summary

Fields

Modifier and Type	Field	Description
private static int	ADDITIONAL_AVG_SCALE	The additional precision and scale in decimal digits for an AVG aggregate function.
private static int	ADDITIONAL_SUM_PRECISION	The additional result precision in decimal digits for a SUM aggregate function.
private static java.util.HashMap<java.lang.String,AggregateType>	AGGREGATES
private AggregateType	aggregateType
private java.lang.Object	extraArguments
private int	flags
private java.util.ArrayList<QueryOrderBy>	orderByList
private SortOrder	orderBySort

Fields inherited from class org.h2.expression.aggregate.AbstractAggregate

args, distinct, filterCondition, type

Fields inherited from class org.h2.expression.analysis.DataAnalysisOperation

over, overOrderBySort, select, STAGE_GROUP, STAGE_RESET, STAGE_WINDOW

Fields inherited from class org.h2.expression.Expression

AUTO_PARENTHESES, MAP_IN_AGGREGATE, MAP_IN_WINDOW, MAP_INITIAL, WITH_PARENTHESES, WITHOUT_PARENTHESES

Fields inherited from interface org.h2.util.HasSQL

ADD_PLAN_INFORMATION, DEFAULT_SQL_FLAGS, NO_CASTS, QUOTE_ONLY_WHEN_REQUIRED, REPLACE_LOBS_FOR_TRACE, TRACE_SQL_FLAGS

Constructor Summary

Constructors

Constructor	Description
Aggregate(AggregateType aggregateType, Expression[] args, Select select, boolean distinct)	Create a new aggregate object.

Method Summary

Modifier and Type	Method	Description
private static void	addAggregate(java.lang.String name, AggregateType type)
private static Value	collect(SessionLocal session, AggregateDataCollecting c, AggregateData d)
protected java.lang.Object	createAggregateData()	Create aggregate data object specific to the subclass.
Value	getAggregatedValue(SessionLocal session, java.lang.Object aggregateData)	Returns aggregated value.
AggregateType	getAggregateType()	Returns the type of this aggregate.
static AggregateType	getAggregateType(java.lang.String name)	Get the aggregate type for this name, or -1 if no aggregate has been found.
private static TypeInfo	getAvgType(TypeInfo type)
int	getCost()	Estimate the cost to process the expression.
private static Value	getCumeDist(Value[] ordered, Value arg, java.util.Comparator<Value> sort)
java.lang.Object	getExtraArguments()	Returns the additional arguments.
int	getFlags()	Returns the flags.
private Value	getHistogram(SessionLocal session, AggregateData data)
private Value	getHypotheticalSet(SessionLocal session, AggregateData data)
private Value	getListagg(SessionLocal session, AggregateData data)
private java.lang.StringBuilder	getListaggError(Value[] array, java.lang.String separator)
private java.lang.String	getListaggItem(Value v)
private java.lang.StringBuilder	getListaggTruncate(Value[] array, java.lang.String separator, java.lang.String filter, boolean withoutCount)
private Index	getMinMaxColumnIndex()
private Value	getMode(SessionLocal session, AggregateData data)
protected int	getNumExpressions()	Returns the number of expressions, excluding OVER clause.
private Value	getRank(Value[] ordered, Value arg, java.util.Comparator<Value> sort)
private Value	getSecondValue(SessionLocal session, Value[] remembered)
Select	getSelect()	Returns the select statement.
private java.lang.StringBuilder	getSQLArrayAggregate(java.lang.StringBuilder builder, int sqlFlags)
private java.lang.StringBuilder	getSQLJsonArrayAggregate(java.lang.StringBuilder builder, int sqlFlags)
private java.lang.StringBuilder	getSQLJsonObjectAggregate(java.lang.StringBuilder builder, int sqlFlags)
private java.lang.StringBuilder	getSQLListagg(java.lang.StringBuilder builder, int sqlFlags)
private static TypeInfo	getSumType(TypeInfo type)
java.lang.StringBuilder	getUnenclosedSQL(java.lang.StringBuilder builder, int sqlFlags)	Get the SQL statement of this expression.
Value	getValue(SessionLocal session)	Return the resulting value for the current row.
private Value	getValueQuick(SessionLocal session)
boolean	isDistinct()	Returns if distinct is used.
boolean	isEverything(ExpressionVisitor visitor)	Check if this expression and all sub-expressions can fulfill a criteria.
void	mapColumnsAnalysis(ColumnResolver resolver, int level, int innerState)	Map the columns of the resolver to expression columns.
Expression	optimize(SessionLocal session)	Try to optimize the expression.
protected void	rememberExpressions(SessionLocal session, Value[] array)	Stores current values of expressions into the specified array.
void	setEvaluatable(TableFilter tableFilter, boolean b)	Tell the expression columns whether the table filter can return values now.
void	setExtraArguments(java.lang.Object extraArguments)	Sets the additional arguments.
void	setFlags(int flags)	Set the flags for this expression.
void	setOrderByList(java.util.ArrayList<QueryOrderBy> orderByList)	Set the order for ARRAY_AGG() or GROUP_CONCAT() aggregate.
private void	sortWithOrderBy(Value[] array)
protected void	updateAggregate(SessionLocal session, java.lang.Object aggregateData)	Updates an aggregate value.
private Value	updateCollecting(SessionLocal session, Value v, Value[] remembered)
private void	updateData(SessionLocal session, AggregateData data, Value v, Value[] remembered)
protected void	updateFromExpressions(SessionLocal session, java.lang.Object aggregateData, Value[] array)	Updates the provided aggregate data from the remembered expressions.
protected void	updateGroupAggregates(SessionLocal session, int stage)	Invoked when processing group stage of grouped window queries to update arguments of this aggregate.

Methods inherited from class org.h2.expression.aggregate.AbstractAggregate

appendTailConditions, getOrderedResultLoop, getSubexpression, getSubexpressionCount, getType, isAggregate, setFilterCondition, updateAggregate

Methods inherited from class org.h2.expression.analysis.DataAnalysisOperation

createOrder, getGroupData, getOverOrderBySort, getWindowData, mapColumns, setOverCondition, updateAggregate, updateOrderedAggregate

Methods inherited from class org.h2.expression.Expression

addFilterConditions, createIndexConditions, getAlias, getBooleanValue, getColumnName, getColumnNameForView, getEnclosedSQL, getNonAliasExpression, getNotIfPossible, getNullable, getSchemaName, getSQL, getSQL, getSQL, getSQL, getTableAlias, getTableName, getWhenSQL, getWhenValue, isConstant, isIdentity, isNullConstant, isValueSet, isWhenConditionOperand, needParentheses, optimizeCondition, toString, writeExpressions, writeExpressions

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.h2.util.HasSQL

getTraceSQL

Field Detail

ADDITIONAL_SUM_PRECISION

private static final int ADDITIONAL_SUM_PRECISION

The additional result precision in decimal digits for a SUM aggregate function.

See Also:

Constant Field Values

ADDITIONAL_AVG_SCALE

private static final int ADDITIONAL_AVG_SCALE

The additional precision and scale in decimal digits for an AVG aggregate function.

See Also:

Constant Field Values

AGGREGATES

private static final java.util.HashMap<java.lang.String,AggregateType> AGGREGATES

aggregateType

private final AggregateType aggregateType

orderByList

private java.util.ArrayList<QueryOrderBy> orderByList

orderBySort

private SortOrder orderBySort

extraArguments

private java.lang.Object extraArguments

flags

private int flags

Constructor Detail

Aggregate

public Aggregate(AggregateType aggregateType,
                 Expression[] args,
                 Select select,
                 boolean distinct)

Create a new aggregate object.

Parameters:

aggregateType - the aggregate type

args - the aggregated expressions

select - the select statement

distinct - if distinct is used

Method Detail

addAggregate

private static void addAggregate(java.lang.String name,
                                 AggregateType type)

getAggregateType

public static AggregateType getAggregateType(java.lang.String name)

Get the aggregate type for this name, or -1 if no aggregate has been found.

Parameters:

name - the aggregate function name

Returns:

null if no aggregate function has been found, or the aggregate type

setOrderByList

public void setOrderByList(java.util.ArrayList<QueryOrderBy> orderByList)

Set the order for ARRAY_AGG() or GROUP_CONCAT() aggregate.

Parameters:

orderByList - the order by list

getAggregateType

public AggregateType getAggregateType()

Returns the type of this aggregate.

Returns:

the type of this aggregate

setExtraArguments

public void setExtraArguments(java.lang.Object extraArguments)

Sets the additional arguments.

Parameters:

extraArguments - the additional arguments

getExtraArguments

public java.lang.Object getExtraArguments()

Returns the additional arguments.

Returns:

the additional arguments

setFlags

public void setFlags(int flags)

Description copied from interface: ExpressionWithFlags

Set the flags for this expression.

Specified by:

setFlags in interface ExpressionWithFlags

Parameters:

flags - the flags to set

getFlags

public int getFlags()

Description copied from interface: ExpressionWithFlags

Returns the flags.

Specified by:

getFlags in interface ExpressionWithFlags

Returns:

the flags

sortWithOrderBy

private void sortWithOrderBy(Value[] array)

updateAggregate

protected void updateAggregate(SessionLocal session,
                               java.lang.Object aggregateData)

Description copied from class: AbstractAggregate

Updates an aggregate value.

Specified by:

updateAggregate in class AbstractAggregate

Parameters:

session - the session

aggregateData - aggregate data

updateData

private void updateData(SessionLocal session,
                        AggregateData data,
                        Value v,
                        Value[] remembered)

getSecondValue

private Value getSecondValue(SessionLocal session,
                             Value[] remembered)

updateGroupAggregates

protected void updateGroupAggregates(SessionLocal session,
                                     int stage)

Description copied from class: DataAnalysisOperation

Invoked when processing group stage of grouped window queries to update arguments of this aggregate.

Overrides:

updateGroupAggregates in class AbstractAggregate

Parameters:

session - the session

stage - select stage

updateCollecting

private Value updateCollecting(SessionLocal session,
                               Value v,
                               Value[] remembered)

getNumExpressions

protected int getNumExpressions()

Description copied from class: DataAnalysisOperation

Returns the number of expressions, excluding OVER clause.

Specified by:

getNumExpressions in class DataAnalysisOperation

Returns:

the number of expressions

rememberExpressions

protected void rememberExpressions(SessionLocal session,
                                   Value[] array)

Description copied from class: DataAnalysisOperation

Stores current values of expressions into the specified array.

Specified by:

rememberExpressions in class DataAnalysisOperation

Parameters:

session - the session

array - array to store values of expressions

updateFromExpressions

protected void updateFromExpressions(SessionLocal session,
                                     java.lang.Object aggregateData,
                                     Value[] array)

Description copied from class: AbstractAggregate

Updates the provided aggregate data from the remembered expressions.

Specified by:

updateFromExpressions in class AbstractAggregate

Parameters:

session - the session

aggregateData - aggregate data

array - values of expressions

createAggregateData

protected java.lang.Object createAggregateData()

Description copied from class: DataAnalysisOperation

Create aggregate data object specific to the subclass.

Specified by:

createAggregateData in class DataAnalysisOperation

Returns:

aggregate-specific data object.

getValue

public Value getValue(SessionLocal session)

Description copied from class: Expression

Return the resulting value for the current row.

Overrides:

getValue in class DataAnalysisOperation

Parameters:

session - the session

Returns:

the result

getValueQuick

private Value getValueQuick(SessionLocal session)

getAggregatedValue

public Value getAggregatedValue(SessionLocal session,
                                java.lang.Object aggregateData)

Description copied from class: DataAnalysisOperation

Returns aggregated value.

Specified by:

getAggregatedValue in class DataAnalysisOperation

Parameters:

session - the session

aggregateData - the aggregate data

Returns:

aggregated value.

collect

private static Value collect(SessionLocal session,
                             AggregateDataCollecting c,
                             AggregateData d)

getHypotheticalSet

private Value getHypotheticalSet(SessionLocal session,
                                 AggregateData data)

getRank

private Value getRank(Value[] ordered,
                      Value arg,
                      java.util.Comparator<Value> sort)

getCumeDist

private static Value getCumeDist(Value[] ordered,
                                 Value arg,
                                 java.util.Comparator<Value> sort)

getListagg

private Value getListagg(SessionLocal session,
                         AggregateData data)

getListaggError

private java.lang.StringBuilder getListaggError(Value[] array,
                                                java.lang.String separator)

getListaggTruncate

private java.lang.StringBuilder getListaggTruncate(Value[] array,
                                                   java.lang.String separator,
                                                   java.lang.String filter,
                                                   boolean withoutCount)

getListaggItem

private java.lang.String getListaggItem(Value v)

getHistogram

private Value getHistogram(SessionLocal session,
                           AggregateData data)

getMode

private Value getMode(SessionLocal session,
                      AggregateData data)

mapColumnsAnalysis

public void mapColumnsAnalysis(ColumnResolver resolver,
                               int level,
                               int innerState)

Description copied from class: DataAnalysisOperation

Map the columns of the resolver to expression columns.

Overrides:

mapColumnsAnalysis in class AbstractAggregate

Parameters:

resolver - the column resolver

level - the subquery nesting level

innerState - one of the Expression MAP_IN_* values

optimize

public Expression optimize(SessionLocal session)

Description copied from class: Expression

Try to optimize the expression.

Overrides:

optimize in class AbstractAggregate

Parameters:

session - the session

Returns:

the optimized expression

getSumType

private static TypeInfo getSumType(TypeInfo type)

getAvgType

private static TypeInfo getAvgType(TypeInfo type)

setEvaluatable

public void setEvaluatable(TableFilter tableFilter,
                           boolean b)

Description copied from class: Expression

Tell the expression columns whether the table filter can return values now. This is used when optimizing the query.

Overrides:

setEvaluatable in class AbstractAggregate

Parameters:

tableFilter - the table filter

b - true if the table filter can return value

getUnenclosedSQL

public java.lang.StringBuilder getUnenclosedSQL(java.lang.StringBuilder builder,
                                                int sqlFlags)

Description copied from class: Expression

Get the SQL statement of this expression. This may not always be the original SQL statement, especially after optimization. Enclosing '(' and ')' are never appended.

Specified by:

getUnenclosedSQL in class Expression

Parameters:

builder - string builder

sqlFlags - formatting flags

Returns:

the specified string builder

getSQLArrayAggregate

private java.lang.StringBuilder getSQLArrayAggregate(java.lang.StringBuilder builder,
                                                     int sqlFlags)

getSQLListagg

private java.lang.StringBuilder getSQLListagg(java.lang.StringBuilder builder,
                                              int sqlFlags)

getSQLJsonObjectAggregate

private java.lang.StringBuilder getSQLJsonObjectAggregate(java.lang.StringBuilder builder,
                                                          int sqlFlags)

getSQLJsonArrayAggregate

private java.lang.StringBuilder getSQLJsonArrayAggregate(java.lang.StringBuilder builder,
                                                         int sqlFlags)

getMinMaxColumnIndex

private Index getMinMaxColumnIndex()

isEverything

public boolean isEverything(ExpressionVisitor visitor)

Description copied from class: Expression

Check if this expression and all sub-expressions can fulfill a criteria. If any part returns false, the result is false.

Overrides:

isEverything in class DataAnalysisOperation

Parameters:

visitor - the visitor

Returns:

if the criteria can be fulfilled

getCost

public int getCost()

Description copied from class: Expression

Estimate the cost to process the expression. Used when optimizing the query, to calculate the query plan with the lowest estimated cost.

Specified by:

getCost in class Expression

Returns:

the estimated cost

getSelect

public Select getSelect()

Returns the select statement.

Returns:

the select statement

isDistinct

public boolean isDistinct()

Returns if distinct is used.

Returns:

if distinct is used