org.apache.flink.table.expressions.resolver.lookups

Class FieldReferenceLookup

java.lang.Object

org.apache.flink.table.expressions.resolver.lookups.FieldReferenceLookup

@Internal
public class FieldReferenceLookup
extends Object

Provides a way to look up field reference by the name of the field.

Constructor Summary

Constructors

Constructor and Description
FieldReferenceLookup(List<QueryOperation> queryOperations)

Method Summary

Modifier and Type	Method and Description
List<FieldReferenceExpression>	getAllInputFields() Gives all fields of underlying inputs in order of those inputs and order of fields within input.
Optional<FieldReferenceExpression>	lookupField(String name) Tries to resolve FieldReferenceExpression using given name in underlying inputs.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FieldReferenceLookup

public FieldReferenceLookup(List<QueryOperation> queryOperations)

Method Detail

lookupField

public Optional<FieldReferenceExpression> lookupField(String name)

Tries to resolve FieldReferenceExpression using given name in underlying inputs.

Parameters:

name - name of field to look for

Returns:

resolved field reference or empty if could not find field with given name.

Throws:

ValidationException - if the name is ambiguous.

getAllInputFields

public List<FieldReferenceExpression> getAllInputFields()

Gives all fields of underlying inputs in order of those inputs and order of fields within input.

Returns:

concatenated list of fields of all inputs.