org.apache.beam.sdk.schemas.transforms

Class Select.Fields<T>

java.lang.Object

org.apache.beam.sdk.transforms.PTransform<PCollection<T>,PCollection<Row>>

org.apache.beam.sdk.schemas.transforms.Select.Fields<T>

All Implemented Interfaces:

java.io.Serializable, HasDisplayData

Enclosing class:

Select

public abstract static class Select.Fields<T>
extends PTransform<PCollection<T>,PCollection<Row>>

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.beam.sdk.transforms.PTransform

name

Constructor Summary

Constructors

Constructor and Description
Fields()

Method Summary

Modifier and Type	Method and Description
PCollection<Row>	expand(PCollection<T> input) Override this method to specify how this PTransform should be expanded on the given InputT.
Select.Fields<T>	withFieldNameAs(java.lang.String fieldName, java.lang.String fieldRename) Add a single field to the selection, along with the name the field should take in the selected schema.
Select.Fields<T>	withOutputSchema(Schema schema) Rename all output fields to match the specified schema.

Methods inherited from class org.apache.beam.sdk.transforms.PTransform

compose, compose, getAdditionalInputs, getDefaultOutputCoder, getDefaultOutputCoder, getDefaultOutputCoder, getKindString, getName, populateDisplayData, toString, validate

Methods inherited from class java.lang.Object

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

Constructor Detail

Fields

public Fields()

Method Detail

withFieldNameAs

public Select.Fields<T> withFieldNameAs(java.lang.String fieldName,
                                        java.lang.String fieldRename)

Add a single field to the selection, along with the name the field should take in the selected schema. This Allows easily renaming fields while doing a select. In cases where the output of a select would otherwise contain conflicting names, this function must be used to rename one of the fields.

withOutputSchema

public Select.Fields<T> withOutputSchema(Schema schema)

Rename all output fields to match the specified schema. If the specified schema is not compatible with the output schema a failure will be raised.

expand

public PCollection<Row> expand(PCollection<T> input)

Description copied from class: PTransform

Override this method to specify how this PTransform should be expanded on the given InputT.

NOTE: This method should not be called directly. Instead apply the PTransform should be applied to the InputT using the apply method.

Composite transforms, which are defined in terms of other transforms, should return the output of one of the composed transforms. Non-composite transforms, which do not apply any transforms internally, should return a new unbound output and register evaluators (via backend-specific registration methods).

Specified by:

expand in class PTransform<PCollection<T>,PCollection<Row>>