Package dev.frostlake.functions.scalar.conditional

Class EqualNull

java.lang.Object

dev.frostlake.functions.BuiltInFunction

dev.frostlake.functions.scalar.conditional.EqualNull

public class EqualNull
extends BuiltInFunction

EQUAL_NULL(a, b) — NULL-safe equality: returns TRUE if both NULL, TRUE if equal, FALSE otherwise.

Constructor Summary

Constructors

Constructor	Description
EqualNull()

Method Summary

Modifier and Type	Method	Description
Object	evaluate(List<Object> args)	Computes the function's result over its already-evaluated argument values.
SemiStructuredRejection	geoRejection(int position)	A GEOSPATIAL value does not COMPARE, where an OBJECT does.
int	getMaxArgCount()	The most arguments a call to this function may pass; Integer.MAX_VALUE marks a variadic function (see BuiltInFunction.isVariadic()).
int	getMinArgCount()	The fewest arguments a call to this function may pass; fewer is an argument-count error.

Methods inherited from class dev.frostlake.functions.BuiltInFunction

approximateRejection, binaryRejection, booleanRejection, evaluate, fileRejection, getName, getReturnType, isVariadic, refusesMissingArgumentsByType, semiStructuredRejection, structuredRejection, temporalRejection, temporalRejection, temporalRejection, textRejection, uuidRejection, vectorRejection

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

EqualNull

public EqualNull()

Method Details

geoRejection

public SemiStructuredRejection geoRejection(int position)

A GEOSPATIAL value does not COMPARE, where an OBJECT does. Live, EQUAL_NULL(o, o) returns TRUE while EQUAL_NULL(g, g) is "Invalid argument types for function 'EQUAL_NULL': (GEOGRAPHY, GEOGRAPHY)" (SQLSTATE 42P13) — the same refusal the bare = operator gives, and the sentence the IS DISTINCT FROM spelling reports too.

Overrides:

geoRejection in class BuiltInFunction

Parameters:

position - the zero-based argument position being asked about

Returns:

the refusal this position gives a GEOGRAPHY or GEOMETRY value; by default, the union of the two semi-structured answers

evaluate

public Object evaluate(List<Object> args)

Description copied from class: BuiltInFunction

Computes the function's result over its already-evaluated argument values. A SQL NULL argument arrives as Java null, and returning null makes the SQL result NULL.

Specified by:

evaluate in class BuiltInFunction

Parameters:

args - the argument values, in call order

Returns:

the function's value for these arguments, or null for SQL NULL

getMinArgCount

public int getMinArgCount()

Description copied from class: BuiltInFunction

The fewest arguments a call to this function may pass; fewer is an argument-count error.

Specified by:

getMinArgCount in class BuiltInFunction

Returns:

the minimum accepted argument count

getMaxArgCount

public int getMaxArgCount()

Description copied from class: BuiltInFunction

The most arguments a call to this function may pass; Integer.MAX_VALUE marks a variadic function (see BuiltInFunction.isVariadic()).

Specified by:

getMaxArgCount in class BuiltInFunction

Returns:

the maximum accepted argument count