org.apache.iotdb.db.query.expression

类 Expression

java.lang.Object

org.apache.iotdb.db.query.expression.Expression

直接已知子类:

BinaryExpression, ConstantOperand, FunctionExpression, NegationExpression, TimeSeriesOperand

public abstract class Expression
extends Object

A skeleton class for expression

字段概要

字段

限定符和类型	字段和说明
protected Boolean	isConstantOperandCache

构造器概要

构造器

构造器和说明
Expression()

方法概要

限定符和类型	方法和说明
abstract void	collectPaths(Set<PartialPath> pathSet)
abstract void	concat(List<PartialPath> prefixPaths, List<Expression> resultExpressions)
abstract IntermediateLayer	constructIntermediateLayer(long queryId, UDTFPlan udtfPlan, RawQueryInputLayer rawTimeSeriesInputLayer, Map<Expression,IntermediateLayer> expressionIntermediateLayerMap, Map<Expression,TSDataType> expressionDataTypeMap, LayerMemoryAssigner memoryAssigner)
abstract void	constructUdfExecutors(Map<String,UDTFExecutor> expressionName2Executor, ZoneId zoneId)
boolean	equals(Object o) Sub-classes must not override this method.
abstract List<Expression>	getExpressions() returns the DIRECT children expressions if it has any, otherwise an EMPTY list will be returned
String	getExpressionString() Get the representation of the expression in string.
protected abstract String	getExpressionStringInternal() Sub-classes should override this method to provide valid string representation of this object.
int	hashCode() Sub-classes must not override this method.
boolean	isConstantOperand() If this expression and all of its sub-expressions are ConstantOperand.
protected abstract boolean	isConstantOperandInternal() Sub-classes should override this method indicating if the expression is a constant operand
boolean	isPlainAggregationFunctionExpression()
boolean	isTimeSeriesGeneratingFunctionExpression()
boolean	isUserDefinedAggregationFunctionExpression()
Iterator<Expression>	iterator() returns an iterator to traverse all the successor expressions in a level-order
abstract void	removeWildcards(WildcardsRemover wildcardsRemover, List<Expression> resultExpressions)
String	toString() Sub-classes must not override this method.
abstract void	updateStatisticsForMemoryAssigner(LayerMemoryAssigner memoryAssigner)

从类继承的方法 java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

字段详细资料

isConstantOperandCache

protected Boolean isConstantOperandCache

构造器详细资料

Expression

public Expression()

方法详细资料

isPlainAggregationFunctionExpression

public boolean isPlainAggregationFunctionExpression()

isUserDefinedAggregationFunctionExpression

public boolean isUserDefinedAggregationFunctionExpression()

isTimeSeriesGeneratingFunctionExpression

public boolean isTimeSeriesGeneratingFunctionExpression()

concat

public abstract void concat(List<PartialPath> prefixPaths,
                            List<Expression> resultExpressions)

removeWildcards

public abstract void removeWildcards(WildcardsRemover wildcardsRemover,
                                     List<Expression> resultExpressions)
                              throws LogicalOptimizeException

抛出:

LogicalOptimizeException

collectPaths

public abstract void collectPaths(Set<PartialPath> pathSet)

constructUdfExecutors

public abstract void constructUdfExecutors(Map<String,UDTFExecutor> expressionName2Executor,
                                           ZoneId zoneId)

updateStatisticsForMemoryAssigner

public abstract void updateStatisticsForMemoryAssigner(LayerMemoryAssigner memoryAssigner)

constructIntermediateLayer

public abstract IntermediateLayer constructIntermediateLayer(long queryId,
                                                             UDTFPlan udtfPlan,
                                                             RawQueryInputLayer rawTimeSeriesInputLayer,
                                                             Map<Expression,IntermediateLayer> expressionIntermediateLayerMap,
                                                             Map<Expression,TSDataType> expressionDataTypeMap,
                                                             LayerMemoryAssigner memoryAssigner)
                                                      throws QueryProcessException,
                                                             IOException

抛出:

QueryProcessException

IOException

isConstantOperandInternal

protected abstract boolean isConstantOperandInternal()

Sub-classes should override this method indicating if the expression is a constant operand

getExpressions

public abstract List<Expression> getExpressions()

returns the DIRECT children expressions if it has any, otherwise an EMPTY list will be returned

isConstantOperand

public final boolean isConstantOperand()

If this expression and all of its sub-expressions are ConstantOperand.

getExpressionStringInternal

protected abstract String getExpressionStringInternal()

Sub-classes should override this method to provide valid string representation of this object. See getExpressionString()

getExpressionString

public final String getExpressionString()

Get the representation of the expression in string. The hash code of the returned value will be the hash code of this object. See hashCode() and equals(Object). In other words, same expressions should have exactly the same string representation, and different expressions must have different string representations.

hashCode

public final int hashCode()

Sub-classes must not override this method.

覆盖:

hashCode 在类中 Object

equals

public final boolean equals(Object o)

Sub-classes must not override this method.

覆盖:

equals 在类中 Object

toString

public final String toString()

Sub-classes must not override this method.

覆盖:

toString 在类中 Object

iterator

public final Iterator<Expression> iterator()

returns an iterator to traverse all the successor expressions in a level-order