org.h2.expression.aggregate

类 JavaAggregate

java.lang.Object

org.h2.expression.Expression

org.h2.expression.analysis.DataAnalysisOperation

org.h2.expression.aggregate.AbstractAggregate

org.h2.expression.aggregate.JavaAggregate

所有已实现的接口:

HasSQL, Typed

public class JavaAggregate
extends AbstractAggregate

This class wraps a user-defined aggregate.

字段概要

从类继承的字段 org.h2.expression.aggregate.AbstractAggregate

args, distinct, filterCondition, type

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

构造器概要

构造器

构造器和说明
JavaAggregate(UserAggregate userAggregate, Expression[] args, Select select, boolean distinct)

方法概要

限定符和类型	方法和说明
protected Object	createAggregateData() Create aggregate data object specific to the subclass.
Value	getAggregatedValue(SessionLocal session, Object aggregateData) Returns aggregated value.
int	getCost() Estimate the cost to process the expression.
protected int	getNumExpressions() Returns the number of expressions, excluding OVER clause.
StringBuilder	getUnenclosedSQL(StringBuilder builder, int sqlFlags) Get the SQL statement of this expression.
boolean	isEverything(ExpressionVisitor visitor) Check if this expression and all sub-expressions can fulfill a criteria.
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.
protected void	updateAggregate(SessionLocal session, Object aggregateData) Updates an aggregate value.
protected 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.aggregate.AbstractAggregate

appendTailConditions, getFilterCondition, getOrderedResultLoop, getSubexpression, getSubexpressionCount, getType, isAggregate, mapColumnsAnalysis, setEvaluatable, setFilterCondition, updateAggregate

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

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

从类继承的方法 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

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

构造器详细资料

JavaAggregate

public JavaAggregate(UserAggregate userAggregate,
                     Expression[] args,
                     Select select,
                     boolean distinct)

方法详细资料

getCost

public int getCost()

从类复制的说明: Expression

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

指定者:

getCost 在类中 Expression

返回:

the estimated cost

getUnenclosedSQL

public StringBuilder getUnenclosedSQL(StringBuilder builder,
                                      int sqlFlags)

从类复制的说明: 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.

指定者:

getUnenclosedSQL 在类中 Expression

参数:

builder - string builder

sqlFlags - formatting flags

返回:

the specified string builder

isEverything

public boolean isEverything(ExpressionVisitor visitor)

从类复制的说明: Expression

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

覆盖:

isEverything 在类中 DataAnalysisOperation

参数:

visitor - the visitor

返回:

if the criteria can be fulfilled

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 AbstractAggregate

参数:

session - the session

返回:

the optimized expression

getAggregatedValue

public Value getAggregatedValue(SessionLocal session,
                                Object aggregateData)

从类复制的说明: DataAnalysisOperation

Returns aggregated value.

指定者:

getAggregatedValue 在类中 DataAnalysisOperation

参数:

session - the session

aggregateData - the aggregate data

返回:

aggregated value.

updateAggregate

protected void updateAggregate(SessionLocal session,
                               Object aggregateData)

从类复制的说明: AbstractAggregate

Updates an aggregate value.

指定者:

updateAggregate 在类中 AbstractAggregate

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 AbstractAggregate

参数:

session - the session

stage - select stage

getNumExpressions

protected int getNumExpressions()

从类复制的说明: DataAnalysisOperation

Returns the number of expressions, excluding OVER clause.

指定者:

getNumExpressions 在类中 DataAnalysisOperation

返回:

the number of expressions

rememberExpressions

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

从类复制的说明: DataAnalysisOperation

Stores current values of expressions into the specified array.

指定者:

rememberExpressions 在类中 DataAnalysisOperation

参数:

session - the session

array - array to store values of expressions

updateFromExpressions

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

从类复制的说明: AbstractAggregate

Updates the provided aggregate data from the remembered expressions.

指定者:

updateFromExpressions 在类中 AbstractAggregate

参数:

session - the session

aggregateData - aggregate data

array - values of expressions

createAggregateData

protected Object createAggregateData()

从类复制的说明: DataAnalysisOperation

Create aggregate data object specific to the subclass.

指定者:

createAggregateData 在类中 DataAnalysisOperation

返回:

aggregate-specific data object.