Package org.apache.flink.table.expressions

Class FieldReferenceExpression

java.lang.Object

org.apache.flink.table.expressions.FieldReferenceExpression

All Implemented Interfaces:

Expression, ResolvedExpression

@PublicEvolving
public final class FieldReferenceExpression
extends Object
implements ResolvedExpression

A reference to a field in an input. The reference contains:

• type
• index of an input the field belongs to
• index of a field within the corresponding input
• optional: alias of the input, if it needs to be referenced by name

Constructor Summary

Constructors

Constructor	Description
FieldReferenceExpression(String name, DataType dataType, int inputIndex, int fieldIndex)
FieldReferenceExpression(String name, DataType dataType, int inputIndex, int fieldIndex, String inputAlias)

Method Summary

Modifier and Type	Method	Description
<R> R	accept(ExpressionVisitor<R> visitor)
String	asSerializableString()	Returns a string that fully serializes this instance.
String	asSummaryString()	Returns a string that summarizes this expression for printing to a console.
boolean	equals(Object o)
List<Expression>	getChildren()
int	getFieldIndex()
int	getInputIndex()
String	getName()
DataType	getOutputDataType()	Returns the data type of the computation result.
List<ResolvedExpression>	getResolvedChildren()
int	hashCode()
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

FieldReferenceExpression

public FieldReferenceExpression(String name,
 DataType dataType,
 int inputIndex,
 int fieldIndex)

FieldReferenceExpression

public FieldReferenceExpression(String name,
 DataType dataType,
 int inputIndex,
 int fieldIndex,
 @Nullable
 String inputAlias)

Method Details

getName

public String getName()

getInputIndex

public int getInputIndex()

getFieldIndex

public int getFieldIndex()

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

asSerializableString

public String asSerializableString()

Description copied from interface: ResolvedExpression

Returns a string that fully serializes this instance. The serialized string can be used for storing the query in, for example, a Catalog as a view.

Specified by:

asSerializableString in interface ResolvedExpression

Returns:

detailed string for persisting in a catalog

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