org.apache.flink.table.types

类 DataType

java.lang.Object

org.apache.flink.table.types.DataType

所有已实现的接口:

Serializable, AbstractDataType<DataType>

直接已知子类:

AtomicDataType, CollectionDataType, FieldsDataType, KeyValueDataType

@PublicEvolving
public abstract class DataType
extends Object
implements AbstractDataType<DataType>, Serializable

Describes the data type of a value in the table ecosystem. Instances of this class can be used to declare input and/or output types of operations.

The DataType class has two responsibilities: declaring a logical type and giving hints about the physical representation of data to the planner. While the logical type is mandatory, hints are optional but useful at the edges to other APIs.

The logical type is independent of any physical representation and is close to the "data type" terminology of the SQL standard. See LogicalType and its subclasses for more information about available logical types and their properties.

Physical hints are required at the edges of the table ecosystem. Hints indicate the data format that an implementation expects. For example, a data source could express that it produces values for logical timestamps using a Timestamp class instead of using LocalDateTime. With this information, the runtime is able to convert the produced class into its internal data format. In return, a data sink can declare the data format it consumes from the runtime.

另请参阅:

for a list of supported data types and instances of this class., 序列化表格

字段概要

字段

限定符和类型	字段和说明
protected Class<?>	conversionClass
protected LogicalType	logicalType

方法概要

限定符和类型	方法和说明
abstract <R> R	accept(DataTypeVisitor<R> visitor)
boolean	equals(Object o)
abstract List<DataType>	getChildren()
Class<?>	getConversionClass() Returns the corresponding conversion class for representing values.
LogicalType	getLogicalType() Returns the corresponding logical type.
int	hashCode()
String	toString()

从类继承的方法 java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

从接口继承的方法 org.apache.flink.table.types.AbstractDataType

bridgedTo, notNull, nullable

字段详细资料

logicalType

protected final LogicalType logicalType

conversionClass

protected final Class<?> conversionClass

方法详细资料

getLogicalType

public LogicalType getLogicalType()

Returns the corresponding logical type.

返回:

a parameterized instance of LogicalType

getConversionClass

public Class<?> getConversionClass()

Returns the corresponding conversion class for representing values. If no conversion class was defined manually, the default conversion defined by the logical type is used.

返回:

the expected conversion class

另请参阅:

LogicalType.getDefaultConversion()

getChildren

public abstract List<DataType> getChildren()

accept

public abstract <R> R accept(DataTypeVisitor<R> visitor)

toString

public String toString()

覆盖:

toString 在类中 Object

equals

public boolean equals(Object o)

覆盖:

equals 在类中 Object

hashCode

public int hashCode()

覆盖:

hashCode 在类中 Object