Class CharType
- java.lang.Object
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- org.apache.flink.table.types.logical.LogicalType
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- org.apache.flink.table.types.logical.CharType
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- All Implemented Interfaces:
Serializable
@PublicEvolving public final class CharType extends LogicalType
Logical type of a fixed-length character string.The serialized string representation is
CHAR(n)
wheren
is the number of code points.n
must have a value between 1 andInteger.MAX_VALUE
(both inclusive). If no length is specified,n
is equal to 1.For expressing a zero-length character string literal, this type does also support
n
to be 0. However, this is not exposed through the API.A conversion from and to
byte[]
assumes UTF-8 encoding.- See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description static int
DEFAULT_LENGTH
static int
EMPTY_LITERAL_LENGTH
static int
MAX_LENGTH
static int
MIN_LENGTH
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description <R> R
accept(LogicalTypeVisitor<R> visitor)
String
asSerializableString()
Returns a string that fully serializes this instance.String
asSummaryString()
Returns a string that summarizes this type for printing to a console.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.int
getLength()
int
hashCode()
static CharType
ofEmptyLiteral()
The SQL standard defines that character string literals are allowed to be zero-length strings (i.e., to contain no characters) even though it is not permitted to declare a type that is zero.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.LogicalType
conversionSet, copy, getTypeRoot, is, is, isAnyOf, isAnyOf, isNullable, toString, withNullability
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Field Detail
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EMPTY_LITERAL_LENGTH
public static final int EMPTY_LITERAL_LENGTH
- See Also:
- Constant Field Values
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MIN_LENGTH
public static final int MIN_LENGTH
- See Also:
- Constant Field Values
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MAX_LENGTH
public static final int MAX_LENGTH
- See Also:
- Constant Field Values
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DEFAULT_LENGTH
public static final int DEFAULT_LENGTH
- See Also:
- Constant Field Values
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Method Detail
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ofEmptyLiteral
public static CharType ofEmptyLiteral()
The SQL standard defines that character string literals are allowed to be zero-length strings (i.e., to contain no characters) even though it is not permitted to declare a type that is zero.This method enables this special kind of character string.
Zero-length character strings have no serializable string representation.
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getLength
public int getLength()
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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 classLogicalType
- Parameters:
isNullable
- the intended nullability of the copied type- Returns:
- a deep copy
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asSerializableString
public String asSerializableString()
Description copied from class:LogicalType
Returns a string that fully serializes this instance. The serialized string can be used for transmitting or persisting a type.See
LogicalTypeParser
for the reverse operation.- Specified by:
asSerializableString
in classLogicalType
- Returns:
- detailed string for transmission or persistence
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asSummaryString
public String asSummaryString()
Description copied from class:LogicalType
Returns a string that summarizes this type for printing to a console. An implementation might shorten long names or skips very specific properties.Use
LogicalType.asSerializableString()
for a type string that fully serializes this instance.- Overrides:
asSummaryString
in classLogicalType
- Returns:
- summary string of this type for debugging purposes
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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
orlong
can be used as input forBIGINT
independent of the set nullability.- Specified by:
supportsInputConversion
in classLogicalType
- 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()
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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
orlong
can be used as output forBIGINT
if the type is not nullable. If the type is nullable, onlyjava.lang.Long
can represent this.- Specified by:
supportsOutputConversion
in classLogicalType
- 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()
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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 forBIGINT
.- Specified by:
getDefaultConversion
in classLogicalType
- Returns:
- default class to represent values of this logical type
- See Also:
LogicalType.supportsInputConversion(Class)
,LogicalType.supportsOutputConversion(Class)
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getChildren
public List<LogicalType> getChildren()
- Specified by:
getChildren
in classLogicalType
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accept
public <R> R accept(LogicalTypeVisitor<R> visitor)
- Specified by:
accept
in classLogicalType
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equals
public boolean equals(Object o)
- Overrides:
equals
in classLogicalType
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hashCode
public int hashCode()
- Overrides:
hashCode
in classLogicalType
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