- All Implemented Interfaces:
Serializable,Comparable<NullPlacement>,Constable
Controls where
NULL values appear when a column is used as a sort key.
SQL specifies two placements: NULLS_FIRST places all NULL
values before any non-NULL value; NULLS_LAST places them after.
The SQL standard defaults are NULLS_LAST for SortDirection.ASC
and NULLS_FIRST for SortDirection.DESC. These defaults apply
when no explicit placement is specified — see SortSpecification.nullPlacement().
Used by the merge-join comparator to ensure both merge
inputs are compared with the same NULL ordering, and by the sort executor
to honour explicit NULLS FIRST/NULLS LAST clauses (Phase C4+).
-
Nested Class Summary
Nested classes/interfaces inherited from class java.lang.Enum
Enum.EnumDesc<E extends Enum<E>> -
Enum Constant Summary
Enum ConstantsEnum ConstantDescriptionNULLvalues sort before all non-NULLvalues.NULLvalues sort after all non-NULLvalues. -
Method Summary
Modifier and TypeMethodDescriptionstatic NullPlacementReturns the enum constant of this class with the specified name.static NullPlacement[]values()Returns an array containing the constants of this enum class, in the order they are declared.
-
Enum Constant Details
-
NULLS_FIRST
NULLvalues sort before all non-NULLvalues. -
NULLS_LAST
NULLvalues sort after all non-NULLvalues.
-
-
Method Details
-
values
Returns an array containing the constants of this enum class, in the order they are declared.- Returns:
- an array containing the constants of this enum class, in the order they are declared
-
valueOf
Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)- Parameters:
name- the name of the enum constant to be returned.- Returns:
- the enum constant with the specified name
- Throws:
IllegalArgumentException- if this enum class has no constant with the specified nameNullPointerException- if the argument is null
-