org.apache.flink.table.expressions

类 AggregateExpression

java.lang.Object

org.apache.flink.table.expressions.AggregateExpression

所有已实现的接口:

Expression, ResolvedExpression

@PublicEvolving
public class AggregateExpression
extends Object
implements ResolvedExpression

Resolved and validated expression for calling an aggregate function.

A aggregate call contains:

• a FunctionDefinition that identifies the function to be called
• a list of FieldReferenceExpression represents the arguments for aggregate function.
• a CallExpression represents the filter with the aggregate function.
• a DataType represents the result data type of aggregate function.
• distinct indicates whether this is a distinct aggregate function.
• approximate indicates whether this is a approximate aggregate function.
• ignoreNulls indicates whether this aggregate function ignore null value.

Note: currently, the AggregateExpression is only used in SupportsAggregatePushDown.

构造器概要

构造器

构造器和说明
AggregateExpression(FunctionDefinition functionDefinition, List<FieldReferenceExpression> args, CallExpression filterExpression, DataType resultType, boolean distinct, boolean approximate, boolean ignoreNulls)

方法概要

限定符和类型	方法和说明
<R> R	accept(ExpressionVisitor<R> visitor)
String	asSummaryString() Returns a string that summarizes this expression for printing to a console.
boolean	equals(Object o)
List<FieldReferenceExpression>	getArgs()
List<Expression>	getChildren()
Optional<CallExpression>	getFilterExpression()
FunctionDefinition	getFunctionDefinition()
DataType	getOutputDataType() Returns the data type of the computation result.
List<ResolvedExpression>	getResolvedChildren()
int	hashCode()
boolean	isApproximate()
boolean	isDistinct()
boolean	isIgnoreNulls()
String	toString()

从类继承的方法 java.lang.Object

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

从接口继承的方法 org.apache.flink.table.expressions.ResolvedExpression

asSerializableString

构造器详细资料

AggregateExpression

public AggregateExpression(FunctionDefinition functionDefinition,
                           List<FieldReferenceExpression> args,
                           @Nullable
                           CallExpression filterExpression,
                           DataType resultType,
                           boolean distinct,
                           boolean approximate,
                           boolean ignoreNulls)

方法详细资料

getFunctionDefinition

public FunctionDefinition getFunctionDefinition()

isDistinct

public boolean isDistinct()

isApproximate

public boolean isApproximate()

isIgnoreNulls

public boolean isIgnoreNulls()

getArgs

public List<FieldReferenceExpression> getArgs()

getFilterExpression

@Nullable
public Optional<CallExpression> getFilterExpression()

getOutputDataType

public DataType getOutputDataType()

从接口复制的说明: ResolvedExpression

Returns the data type of the computation result.

指定者:

getOutputDataType 在接口中 ResolvedExpression

getResolvedChildren

public List<ResolvedExpression> getResolvedChildren()

指定者:

getResolvedChildren 在接口中 ResolvedExpression

asSummaryString

public String asSummaryString()

从接口复制的说明: Expression

Returns a string that summarizes this expression for printing to a console. An implementation might skip very specific properties.

指定者:

asSummaryString 在接口中 Expression

返回:

summary string of this expression for debugging purposes

getChildren

public List<Expression> getChildren()

指定者:

getChildren 在接口中 Expression

accept

public <R> R accept(ExpressionVisitor<R> visitor)

指定者:

accept 在接口中 Expression

equals

public boolean equals(Object o)

覆盖:

equals 在类中 Object

hashCode

public int hashCode()

覆盖:

hashCode 在类中 Object

toString

public String toString()

覆盖:

toString 在类中 Object