org.apache.spark.ml.feature

Class SQLTransformer

Object

org.apache.spark.ml.PipelineStage

org.apache.spark.ml.Transformer

org.apache.spark.ml.feature.SQLTransformer

All Implemented Interfaces:

java.io.Serializable, Logging, Params, Identifiable

public class SQLTransformer
extends Transformer

:: Experimental :: Implements the transformations which are defined by SQL statement. Currently we only support SQL syntax like 'SELECT ... FROM __THIS__ ...' where '__THIS__' represents the underlying table of the input dataset. The select clause specifies the fields, constants, and expressions to display in the output, it can be any select clause that Spark SQL supports. Users can also use Spark SQL built-in function and UDFs to operate on these selected columns. For example, SQLTransformer supports statements like: - SELECT a, a + b AS a_b FROM __THIS__ - SELECT a, SQRT(b) AS b_sqrt FROM __THIS__ where a > 5 - SELECT a, b, SUM(c) AS c_sum FROM __THIS__ GROUP BY a, b

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
SQLTransformer()
SQLTransformer(String uid)

Method Summary

Methods

Modifier and Type	Method and Description
SQLTransformer	copy(ParamMap extra) Creates a copy of this instance with the same UID and some extra params.
String	getStatement()
static SQLTransformer	load(String path)
SQLTransformer	setStatement(String value)
Param<String>	statement() SQL statement parameter.
DataFrame	transform(DataFrame dataset) Transforms the input dataset.
StructType	transformSchema(StructType schema) :: DeveloperApi ::
String	uid() An immutable unique ID for the object and its derivatives.

Methods inherited from class org.apache.spark.ml.Transformer

transform, transform, transform

Methods inherited from class Object

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

Methods inherited from interface org.apache.spark.ml.param.Params

clear, copyValues, defaultCopy, defaultParamMap, explainParam, explainParams, extractParamMap, extractParamMap, get, getDefault, getOrDefault, getParam, hasDefault, hasParam, isDefined, isSet, paramMap, params, set, set, set, setDefault, setDefault, shouldOwn, validateParams

Methods inherited from interface org.apache.spark.ml.util.Identifiable

toString

Methods inherited from interface org.apache.spark.Logging

initializeIfNecessary, initializeLogging, isTraceEnabled, log_, log, logDebug, logDebug, logError, logError, logInfo, logInfo, logName, logTrace, logTrace, logWarning, logWarning

Constructor Detail

SQLTransformer

public SQLTransformer(String uid)

SQLTransformer

public SQLTransformer()

Method Detail

load

public static SQLTransformer load(String path)

uid

public String uid()

Description copied from interface: Identifiable

An immutable unique ID for the object and its derivatives.

Returns:

(undocumented)

statement

public final Param<String> statement()

SQL statement parameter. The statement is provided in string form.

Returns:

(undocumented)

setStatement

public SQLTransformer setStatement(String value)

getStatement

public String getStatement()

transform

public DataFrame transform(DataFrame dataset)

Description copied from class: Transformer

Transforms the input dataset.

Specified by:

transform in class Transformer

Parameters:

dataset - (undocumented)

Returns:

(undocumented)

transformSchema

public StructType transformSchema(StructType schema)

Description copied from class: PipelineStage

:: DeveloperApi ::

Derives the output schema from the input schema.

Specified by:

transformSchema in class PipelineStage

Parameters:

schema - (undocumented)

Returns:

(undocumented)

copy

public SQLTransformer copy(ParamMap extra)

Description copied from interface: Params

Creates a copy of this instance with the same UID and some extra params. Subclasses should implement this method and set the return type properly.

Specified by:

copy in interface Params

Specified by:

copy in class Transformer

Parameters:

extra - (undocumented)

Returns:

(undocumented)

See Also:

defaultCopy()