org.h2.expression.aggregate

类 AbstractAggregate

java.lang.Object

org.h2.expression.Expression

org.h2.expression.analysis.DataAnalysisOperation

org.h2.expression.aggregate.AbstractAggregate

所有已实现的接口:

HasSQL, Typed

直接已知子类:

Aggregate, JavaAggregate

public abstract class AbstractAggregate
extends DataAnalysisOperation

A base class for aggregate functions.

字段概要

字段

限定符和类型	字段和说明
protected Expression[]	args The arguments.
protected boolean	distinct is this a DISTINCT aggregate
protected Expression	filterCondition FILTER condition for aggregate
protected TypeInfo	type The type of the result.

从类继承的字段 org.h2.expression.analysis.DataAnalysisOperation

over, overOrderBySort, select, STAGE_GROUP, STAGE_RESET, STAGE_WINDOW

从类继承的字段 org.h2.expression.Expression

AUTO_PARENTHESES, MAP_IN_AGGREGATE, MAP_IN_WINDOW, MAP_INITIAL, WITH_PARENTHESES, WITHOUT_PARENTHESES

从接口继承的字段 org.h2.util.HasSQL

ADD_PLAN_INFORMATION, DEFAULT_SQL_FLAGS, NO_CASTS, QUOTE_ONLY_WHEN_REQUIRED, REPLACE_LOBS_FOR_TRACE, TRACE_SQL_FLAGS

方法概要

限定符和类型	方法和说明
protected StringBuilder	appendTailConditions(StringBuilder builder, int sqlFlags, boolean forceOrderBy) Used to create SQL for the OVER and FILTER clauses.
Expression	getFilterCondition() Returns the FILTER condition.
protected void	getOrderedResultLoop(SessionLocal session, HashMap<Integer,Value> result, ArrayList<Value[]> ordered, int rowIdColumn) Returns result of this window function or window aggregate.
Expression	getSubexpression(int index) Returns subexpression with specified index.
int	getSubexpressionCount() Returns count of subexpressions.
TypeInfo	getType() Returns the data type.
boolean	isAggregate() Checks whether this expression is an aggregate function.
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.
void	setEvaluatable(TableFilter tableFilter, boolean b) Tell the expression columns whether the table filter can return values now.
void	setFilterCondition(Expression filterCondition) Sets the FILTER condition.
protected abstract void	updateAggregate(SessionLocal session, Object aggregateData) Updates an aggregate value.
protected void	updateAggregate(SessionLocal session, SelectGroups groupData, int groupRowId) Update a row of an aggregate.
protected abstract void	updateFromExpressions(SessionLocal session, 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.

从类继承的方法 org.h2.expression.analysis.DataAnalysisOperation

createAggregateData, createOrder, getAggregatedValue, getGroupData, getNumExpressions, getOverCondition, getOverOrderBySort, getValue, getWindowData, isEverything, mapColumns, rememberExpressions, setOverCondition, updateAggregate, updateOrderedAggregate

从类继承的方法 org.h2.expression.Expression

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

从类继承的方法 java.lang.Object

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

从接口继承的方法 org.h2.util.HasSQL

getTraceSQL

字段详细资料

distinct

protected final boolean distinct

is this a DISTINCT aggregate

args

protected final Expression[] args

The arguments.

filterCondition

protected Expression filterCondition

FILTER condition for aggregate

type

protected TypeInfo type

The type of the result.

方法详细资料

isAggregate

public final boolean isAggregate()

从类复制的说明: DataAnalysisOperation

Checks whether this expression is an aggregate function.

指定者:

isAggregate 在类中 DataAnalysisOperation

返回:

true if this is an aggregate function (including aggregates with OVER clause), false if this is a window function

getFilterCondition

public Expression getFilterCondition()

Returns the FILTER condition.

返回:

the FILTER Condition

setFilterCondition

public void setFilterCondition(Expression filterCondition)

Sets the FILTER condition.

参数:

filterCondition - FILTER condition

getType

public TypeInfo getType()

从类复制的说明: Expression

Returns the data type. The data type may be unknown before the optimization phase.

指定者:

getType 在接口中 Typed

指定者:

getType 在类中 Expression

返回:

the data type

mapColumnsAnalysis

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

从类复制的说明: DataAnalysisOperation

Map the columns of the resolver to expression columns.

覆盖:

mapColumnsAnalysis 在类中 DataAnalysisOperation

参数:

resolver - the column resolver

level - the subquery nesting level

innerState - one of the Expression MAP_IN_* values

optimize

public Expression optimize(SessionLocal session)

从类复制的说明: Expression

Try to optimize the expression.

覆盖:

optimize 在类中 DataAnalysisOperation

参数:

session - the session

返回:

the optimized expression

setEvaluatable

public void setEvaluatable(TableFilter tableFilter,
                           boolean b)

从类复制的说明: Expression

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

覆盖:

setEvaluatable 在类中 DataAnalysisOperation

参数:

tableFilter - the table filter

b - true if the table filter can return value

getOrderedResultLoop

protected void getOrderedResultLoop(SessionLocal session,
                                    HashMap<Integer,Value> result,
                                    ArrayList<Value[]> ordered,
                                    int rowIdColumn)

从类复制的说明: DataAnalysisOperation

Returns result of this window function or window aggregate. This method may not be called on window aggregate without window order clause.

指定者:

getOrderedResultLoop 在类中 DataAnalysisOperation

参数:

session - the session

result - the map to append result to

ordered - ordered data

rowIdColumn - the index of row id value

updateFromExpressions

protected abstract void updateFromExpressions(SessionLocal session,
                                              Object aggregateData,
                                              Value[] array)

Updates the provided aggregate data from the remembered expressions.

参数:

session - the session

aggregateData - aggregate data

array - values of expressions

updateAggregate

protected void updateAggregate(SessionLocal session,
                               SelectGroups groupData,
                               int groupRowId)

从类复制的说明: DataAnalysisOperation

Update a row of an aggregate.

指定者:

updateAggregate 在类中 DataAnalysisOperation

参数:

session - the database session

groupData - data for the aggregate group

groupRowId - row id of group

updateAggregate

protected abstract void updateAggregate(SessionLocal session,
                                        Object aggregateData)

Updates an aggregate value.

参数:

session - the session

aggregateData - aggregate data

updateGroupAggregates

protected void updateGroupAggregates(SessionLocal session,
                                     int stage)

从类复制的说明: DataAnalysisOperation

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

覆盖:

updateGroupAggregates 在类中 DataAnalysisOperation

参数:

session - the session

stage - select stage

appendTailConditions

protected StringBuilder appendTailConditions(StringBuilder builder,
                                             int sqlFlags,
                                             boolean forceOrderBy)

从类复制的说明: DataAnalysisOperation

Used to create SQL for the OVER and FILTER clauses.

覆盖:

appendTailConditions 在类中 DataAnalysisOperation

参数:

builder - string builder

sqlFlags - formatting flags

forceOrderBy - whether synthetic ORDER BY clause should be generated when it is missing

返回:

the builder object

getSubexpressionCount

public int getSubexpressionCount()

从类复制的说明: Expression

Returns count of subexpressions.

覆盖:

getSubexpressionCount 在类中 Expression

返回:

count of subexpressions

getSubexpression

public Expression getSubexpression(int index)

从类复制的说明: Expression

Returns subexpression with specified index.

覆盖:

getSubexpression 在类中 Expression

参数:

index - 0-based index

返回:

subexpression with specified index, may be null