org.apache.flink.table.expressions

Class AggregateExpression

java.lang.Object

org.apache.flink.table.expressions.AggregateExpression

All Implemented Interfaces:

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.

Constructor Summary

Constructors

Constructor and Description
AggregateExpression(FunctionDefinition functionDefinition, List<FieldReferenceExpression> args, CallExpression filterExpression, DataType resultType, boolean distinct, boolean approximate, boolean ignoreNulls)

Method Summary

Modifier and Type	Method and Description
<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()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.flink.table.expressions.ResolvedExpression

asSerializableString

Constructor Detail

AggregateExpression

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

Method Detail

getFunctionDefinition

public FunctionDefinition getFunctionDefinition()

isDistinct

public boolean isDistinct()

isApproximate

public boolean isApproximate()

isIgnoreNulls

public boolean isIgnoreNulls()

getArgs

public List<FieldReferenceExpression> getArgs()

getFilterExpression

public Optional<CallExpression> getFilterExpression()

getOutputDataType

public DataType getOutputDataType()

Description copied from interface: ResolvedExpression

Returns the data type of the computation result.

Specified by:

getOutputDataType in interface ResolvedExpression

getResolvedChildren

public List<ResolvedExpression> getResolvedChildren()

Specified by:

getResolvedChildren in interface ResolvedExpression

asSummaryString

public String asSummaryString()

Description copied from interface: Expression

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

Specified by:

asSummaryString in interface Expression

Returns:

summary string of this expression for debugging purposes

getChildren

public List<Expression> getChildren()

Specified by:

getChildren in interface Expression

accept

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

Specified by:

accept in interface Expression

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object