Module com.darkcollective.relix.ast

Package com.darkcollective.relix.ast

Enum Class NullPlacement

java.lang.Object

java.lang.Enum<NullPlacement>

com.darkcollective.relix.ast.NullPlacement

All Implemented Interfaces:

Serializable, Comparable<NullPlacement>, Constable

public enum NullPlacement
extends Enum<NullPlacement>

Where NULL values land when a column is used as a sort key.

NULLS_FIRST places every NULL before any non-NULL value; NULLS_LAST places them after. A sort key holds the placement in the output, whichever way the key runs (SortSpecification.nulls()). Relix's default treats NULL as the largest value, as PostgreSQL and Oracle do: NULLS_LAST ascending and NULLS_FIRST descending (SortSpecification.defaultNulls(com.darkcollective.relix.ast.SortDirection)). SQL's NULLS FIRST and NULLS LAST choose. SortSpecification.nullPlacement() gives the same placement as it reads before a descending key is reversed.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Enum

Enum.EnumDesc<E extends Enum<E>>

Enum Constant Summary

Enum Constants

Enum Constant	Description
NULLS_FIRST	NULL values sort before all non-NULL values.
NULLS_LAST	NULL values sort after all non-NULL values.

Method Summary

Modifier and Type	Method	Description
static NullPlacement	valueOf(String name)	Returns 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.

Methods inherited from class java.lang.Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

NULLS_FIRST

public static final NullPlacement NULLS_FIRST

NULL values sort before all non-NULL values.

NULLS_LAST

public static final NullPlacement NULLS_LAST

NULL values sort after all non-NULL values.

Method Details

values

public static NullPlacement[] 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

public static NullPlacement valueOf(String name)

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 name

NullPointerException - if the argument is null