org.apache.flink.table.types.logical

Class DistinctType

java.lang.Object

org.apache.flink.table.types.logical.LogicalType

org.apache.flink.table.types.logical.UserDefinedType

org.apache.flink.table.types.logical.DistinctType

All Implemented Interfaces:

Serializable

@PublicEvolving
public final class DistinctType
extends UserDefinedType

Logical type of a user-defined distinct type. A distinct type specifies an identifier and is backed by a source type. A distinct type has the same internal representation as a source type, but is considered to be a separate and incompatible data type for most operations. Compared to the SQL standard, every non-user-defined type can be used as a source type.

A distinct type can always be cast to its source type and vice versa.

Distinct types are implicitly final and do not support super types.

Most other properties are forwarded from the source type. Thus, ordering and comparison among the same distinct types are supported.

The serialized string representation is the fully qualified name of this type which means that the type must have been registered in a catalog.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DistinctType.Builder A builder for a DistinctType.

Method Summary

Modifier and Type	Method and Description
<R> R	accept(LogicalTypeVisitor<R> visitor)
LogicalType	copy(boolean isNullable) Returns a deep copy of this type with possibly different nullability.
boolean	equals(Object o)
List<LogicalType>	getChildren()
Class<?>	getDefaultConversion() Returns the default conversion class.
LogicalType	getSourceType()
int	hashCode()
static DistinctType.Builder	newBuilder(ObjectIdentifier objectIdentifier, LogicalType sourceType) Creates a builder for a DistinctType.
boolean	supportsInputConversion(Class<?> clazz) Returns whether an instance of the given class can be represented as a value of this logical type when entering the table ecosystem.
boolean	supportsOutputConversion(Class<?> clazz) Returns whether a value of this logical type can be represented as an instance of the given class when leaving the table ecosystem.

Methods inherited from class org.apache.flink.table.types.logical.UserDefinedType

asSerializableString, getDescription, getObjectIdentifier, isFinal

Methods inherited from class org.apache.flink.table.types.logical.LogicalType

asSummaryString, conversionSet, copy, getTypeRoot, is, is, isAnyOf, isAnyOf, isNullable, toString, withNullability

Methods inherited from class java.lang.Object

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

Method Detail

newBuilder

public static DistinctType.Builder newBuilder(ObjectIdentifier objectIdentifier,
                                              LogicalType sourceType)

Creates a builder for a DistinctType.

getSourceType

public LogicalType getSourceType()

copy

public LogicalType copy(boolean isNullable)

Description copied from class: LogicalType

Returns a deep copy of this type with possibly different nullability.

Specified by:

copy in class LogicalType

Parameters:

isNullable - the intended nullability of the copied type

Returns:

a deep copy

supportsInputConversion

public boolean supportsInputConversion(Class<?> clazz)

Description copied from class: LogicalType

Returns whether an instance of the given class can be represented as a value of this logical type when entering the table ecosystem. This method helps for the interoperability between JVM-based languages and the relational type system.

A supported conversion directly maps an input class to a logical type without loss of precision or type widening.

For example, java.lang.Long or long can be used as input for BIGINT independent of the set nullability.

Specified by:

supportsInputConversion in class LogicalType

Parameters:

clazz - input class to be converted into this logical type

Returns:

flag that indicates if instances of this class can be used as input into the table ecosystem

See Also:

LogicalType.getDefaultConversion()

supportsOutputConversion

public boolean supportsOutputConversion(Class<?> clazz)

Description copied from class: LogicalType

Returns whether a value of this logical type can be represented as an instance of the given class when leaving the table ecosystem. This method helps for the interoperability between JVM-based languages and the relational type system.

A supported conversion directly maps a logical type to an output class without loss of precision or type widening.

For example, java.lang.Long or long can be used as output for BIGINT if the type is not nullable. If the type is nullable, only java.lang.Long can represent this.

Specified by:

supportsOutputConversion in class LogicalType

Parameters:

clazz - output class to be converted from this logical type

Returns:

flag that indicates if instances of this class can be used as output from the table ecosystem

See Also:

LogicalType.getDefaultConversion()

getDefaultConversion

public Class<?> getDefaultConversion()

Description copied from class: LogicalType

Returns the default conversion class. A value of this logical type is expected to be an instance of the given class when entering or is represented as an instance of the given class when leaving the table ecosystem if no other conversion has been specified.

For example, java.lang.Long is the default input and output for BIGINT.

Specified by:

getDefaultConversion in class LogicalType

Returns:

default class to represent values of this logical type

See Also:

LogicalType.supportsInputConversion(Class), LogicalType.supportsOutputConversion(Class)

getChildren

public List<LogicalType> getChildren()

Specified by:

getChildren in class LogicalType

accept

public <R> R accept(LogicalTypeVisitor<R> visitor)

Specified by:

accept in class LogicalType

equals

public boolean equals(Object o)

Overrides:

equals in class UserDefinedType

hashCode

public int hashCode()

Overrides:

hashCode in class UserDefinedType