org.apache.flink.table.functions.python

类 PythonTableFunction

java.lang.Object

org.apache.flink.table.functions.UserDefinedFunction

org.apache.flink.table.functions.TableFunction<org.apache.flink.types.Row>

org.apache.flink.table.functions.python.PythonTableFunction

所有已实现的接口:

Serializable, FunctionDefinition, PythonFunction

@Internal
public class PythonTableFunction
extends TableFunction<org.apache.flink.types.Row>
implements PythonFunction

The wrapper of user defined python table function.

另请参阅:

序列化表格

构造器概要

构造器

构造器和说明
PythonTableFunction(String name, byte[] serializedScalarFunction, org.apache.flink.api.common.typeinfo.TypeInformation[] inputTypes, org.apache.flink.api.java.typeutils.RowTypeInfo resultType, PythonFunctionKind pythonFunctionKind, boolean deterministic, PythonEnv pythonEnv)

方法概要

限定符和类型	方法和说明
void	eval(Object... args)
org.apache.flink.api.common.typeinfo.TypeInformation[]	getParameterTypes(Class[] signature) Returns TypeInformation about the operands of the evaluation method with a given signature.
PythonEnv	getPythonEnv() Returns the Python execution environment.
PythonFunctionKind	getPythonFunctionKind() Returns the kind of the user-defined python function.
org.apache.flink.api.common.typeinfo.TypeInformation<org.apache.flink.types.Row>	getResultType() Returns the result type of the evaluation method.
byte[]	getSerializedPythonFunction() Returns the serialized representation of the user-defined python function.
TypeInference	getTypeInference(DataTypeFactory typeFactory) Returns the logic for performing type inference of a call to this function definition.
boolean	isDeterministic() Returns information about the determinism of the function's results.
String	toString() Returns the name of the UDF that is used for plan explanation and logging.

从类继承的方法 org.apache.flink.table.functions.TableFunction

collect, getKind, setCollector

从类继承的方法 org.apache.flink.table.functions.UserDefinedFunction

close, functionIdentifier, open

从类继承的方法 java.lang.Object

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

从接口继承的方法 org.apache.flink.table.functions.FunctionDefinition

getRequirements

构造器详细资料

PythonTableFunction

public PythonTableFunction(String name,
                           byte[] serializedScalarFunction,
                           org.apache.flink.api.common.typeinfo.TypeInformation[] inputTypes,
                           org.apache.flink.api.java.typeutils.RowTypeInfo resultType,
                           PythonFunctionKind pythonFunctionKind,
                           boolean deterministic,
                           PythonEnv pythonEnv)

方法详细资料

eval

public void eval(Object... args)

getSerializedPythonFunction

public byte[] getSerializedPythonFunction()

从接口复制的说明: PythonFunction

Returns the serialized representation of the user-defined python function.

指定者:

getSerializedPythonFunction 在接口中 PythonFunction

getPythonEnv

public PythonEnv getPythonEnv()

从接口复制的说明: PythonFunction

Returns the Python execution environment.

指定者:

getPythonEnv 在接口中 PythonFunction

getPythonFunctionKind

public PythonFunctionKind getPythonFunctionKind()

从接口复制的说明: PythonFunction

Returns the kind of the user-defined python function.

指定者:

getPythonFunctionKind 在接口中 PythonFunction

isDeterministic

public boolean isDeterministic()

从接口复制的说明: FunctionDefinition

Returns information about the determinism of the function's results.

It returns true if and only if a call to this function is guaranteed to always return the same result given the same parameters. true is assumed by default. If the function is not pure functional like random(), date(), now(), ... this method must return false.

指定者:

isDeterministic 在接口中 FunctionDefinition

getParameterTypes

public org.apache.flink.api.common.typeinfo.TypeInformation[] getParameterTypes(Class[] signature)

从类复制的说明: TableFunction

Returns TypeInformation about the operands of the evaluation method with a given signature.

覆盖:

getParameterTypes 在类中 TableFunction<org.apache.flink.types.Row>

getResultType

public org.apache.flink.api.common.typeinfo.TypeInformation<org.apache.flink.types.Row> getResultType()

从类复制的说明: TableFunction

Returns the result type of the evaluation method.

覆盖:

getResultType 在类中 TableFunction<org.apache.flink.types.Row>

getTypeInference

public TypeInference getTypeInference(DataTypeFactory typeFactory)

从类复制的说明: UserDefinedFunction

Returns the logic for performing type inference of a call to this function definition.

The type inference process is responsible for inferring unknown types of input arguments, validating input arguments, and producing result types. The type inference process happens independent of a function body. The output of the type inference is used to search for a corresponding runtime implementation.

Instances of type inference can be created by using TypeInference.newBuilder().

See BuiltInFunctionDefinitions for concrete usage examples.

The type inference for user-defined functions is automatically extracted using reflection. It does this by analyzing implementation methods such as eval() or accumulate() and the generic parameters of a function class if present. If the reflective information is not sufficient, it can be supported and enriched with DataTypeHint and FunctionHint annotations.

Note: Overriding this method is only recommended for advanced users. If a custom type inference is specified, it is the responsibility of the implementer to make sure that the output of the type inference process matches with the implementation method:

The implementation method must comply with each DataType.getConversionClass() returned by the type inference. For example, if DataTypes.TIMESTAMP(3).bridgedTo(java.sql.Timestamp.class) is an expected argument type, the method must accept a call eval(java.sql.Timestamp).

Regular Java calling semantics (including type widening and autoboxing) are applied when calling an implementation method which means that the signature can be eval(java.lang.Object).

The runtime will take care of converting the data to the data format specified by the DataType.getConversionClass() coming from the type inference logic.

指定者:

getTypeInference 在接口中 FunctionDefinition

覆盖:

getTypeInference 在类中 TableFunction<org.apache.flink.types.Row>

toString

public String toString()

从类复制的说明: UserDefinedFunction

Returns the name of the UDF that is used for plan explanation and logging.

覆盖:

toString 在类中 UserDefinedFunction