public class SQLTransformer extends Transformer implements DefaultParamsWritable
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
Constructor and Description |
---|
SQLTransformer() |
SQLTransformer(String uid) |
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) |
static MLReader<T> |
read() |
SQLTransformer |
setStatement(String value) |
Param<String> |
statement()
SQL statement parameter.
|
String |
toString() |
Dataset<Row> |
transform(Dataset<?> dataset)
Transforms the input dataset.
|
StructType |
transformSchema(StructType schema)
Check transform validity and derive the output schema from the input schema.
|
String |
uid()
An immutable unique ID for the object and its derivatives.
|
transform, transform, transform
params
write
save
clear, copyValues, defaultCopy, explainParam, explainParams, extractParamMap, extractParamMap, get, getDefault, getOrDefault, getParam, hasDefault, hasParam, isDefined, isSet, onParamChange, set, set, set, setDefault, setDefault, shouldOwn
$init$, initializeForcefully, initializeLogIfNecessary, initializeLogIfNecessary, initializeLogIfNecessary$default$2, initLock, isTraceEnabled, log, logDebug, logDebug, logError, logError, logInfo, logInfo, logName, logTrace, logTrace, logWarning, logWarning, org$apache$spark$internal$Logging$$log__$eq, org$apache$spark$internal$Logging$$log_, uninitialize
public SQLTransformer(String uid)
public SQLTransformer()
public static SQLTransformer load(String path)
public static MLReader<T> read()
public String uid()
Identifiable
uid
in interface Identifiable
public final Param<String> statement()
public SQLTransformer setStatement(String value)
public String getStatement()
public Dataset<Row> transform(Dataset<?> dataset)
Transformer
transform
in class Transformer
dataset
- (undocumented)public StructType transformSchema(StructType schema)
PipelineStage
We check validity for interactions between parameters during transformSchema
and
raise an exception if any parameter value is invalid. Parameter value checks which
do not depend on other parameters are handled by Param.validate()
.
Typical implementation should first conduct verification on schema change and parameter validity, including complex parameter interaction checks.
transformSchema
in class PipelineStage
schema
- (undocumented)public SQLTransformer copy(ParamMap extra)
Params
defaultCopy()
.copy
in interface Params
copy
in class Transformer
extra
- (undocumented)public String toString()
toString
in interface Identifiable
toString
in class Object