Module datarush.library

Package com.pervasive.datarush.operators.record

Class SelectFields

java.lang.Object

com.pervasive.datarush.operators.AbstractLogicalOperator

com.pervasive.datarush.operators.StreamingOperator

com.pervasive.datarush.operators.ExecutableOperator

com.pervasive.datarush.operators.AbstractExecutableRecordPipeline

com.pervasive.datarush.operators.record.FilterFields

com.pervasive.datarush.operators.record.SelectFields

All Implemented Interfaces:

LogicalOperator, PipelineOperator<RecordPort>, RecordPipelineOperator

public class SelectFields
extends FilterFields

Preserves a subset of fields from the input records. While similar to RetainFields, there are two significant behavioral differences:

• the fields are reordered according to their order in the filter
• all fields specified in the filter must exist in the input or an error will be raised.

See Also:

• RemapFields

Field Summary

Fields inherited from class com.pervasive.datarush.operators.AbstractExecutableRecordPipeline

input, output

Constructor Summary

Constructors

Constructor	Description
SelectFields()	Keeps no fields from the input.
SelectFields(RecordTextSchema<?> schema)	Keeps the specified fields from the input schema.
SelectFields(String... fields)	Keeps the specified fields from the input.
SelectFields(List<String> fields)	Keeps the specified fields from the input.

Method Summary

Modifier and Type	Method	Description
RecordPort	getInput()	Gets the record port providing the input data to the operation.
RecordPort	getOutput()	Gets the record port providing the output from the operation.
void	setSelectionSchema(RecordTextSchema<?> schema)	Sets the schema with the names of the fields that will be kept.

Methods inherited from class com.pervasive.datarush.operators.record.FilterFields

computeMetadata, execute, getFieldNames, setFieldNames, setFieldNames

Methods inherited from class com.pervasive.datarush.operators.ExecutableOperator

cloneForExecution, getNumInputCopies, getPortSettings, handleInactiveOutput

Methods inherited from class com.pervasive.datarush.operators.AbstractLogicalOperator

disableParallelism, getInputPorts, getOutputPorts, newInput, newInput, newOutput, newRecordInput, newRecordInput, newRecordOutput, notifyError

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.pervasive.datarush.operators.LogicalOperator

disableParallelism, getInputPorts, getOutputPorts

Constructor Details

SelectFields

public SelectFields()

Keeps no fields from the input. To specify fields to keep, use FilterFields.setFieldNames(String...). If no fields are specified when the containing graph is executed, an error will be raised.

SelectFields

public SelectFields(List<String> fields)

Keeps the specified fields from the input. When the containing graph is executed, an error will be raised if any named field is not present.

Parameters:

fields - the names of fields to keep.

SelectFields

public SelectFields(String... fields)

Keeps the specified fields from the input. When the containing graph is executed, an error will be raised if any named field is not present.

Parameters:

fields - the names of fields to keep.

SelectFields

public SelectFields(RecordTextSchema<?> schema)

Keeps the specified fields from the input schema. When the containing graph is executed, an error will be raised if any named field is not present.

Parameters:

schema - the schema with the fields to keep.

Method Details

setSelectionSchema

public void setSelectionSchema(RecordTextSchema<?> schema)

Sets the schema with the names of the fields that will be kept. The ordering of the fields defines the output order.

Parameters:

schema - the schema that defines the field selection

getInput

public RecordPort getInput()

Description copied from class: AbstractExecutableRecordPipeline

Gets the record port providing the input data to the operation.

Specified by:

getInput in interface PipelineOperator<RecordPort>

Overrides:

getInput in class AbstractExecutableRecordPipeline

Returns:

the input port for the operation

getOutput

public RecordPort getOutput()

Description copied from class: AbstractExecutableRecordPipeline

Gets the record port providing the output from the operation.

Specified by:

getOutput in interface PipelineOperator<RecordPort>

Overrides:

getOutput in class AbstractExecutableRecordPipeline

Returns:

the output port for the operation