ai.grakn.graql

Interface Var

All Superinterfaces:

Pattern

All Known Subinterfaces:

VarAdmin

public interface Var
extends Pattern

A wildcard variable to refers to a concept in a query.

A Var may be given a variable name, or left as an "anonymous" variable. Graql provides static methods for constructing Var objects.

The methods on Var are used to set its properties. A Var behaves differently depending on the type of query its used in. In a MatchQuery, a Var describes the properties any matching concept must have. In an InsertQuery, it describes the properties that should be set on the inserted concept. In a DeleteQuery, it describes the properties that should be deleted.

Method Summary

Modifier and Type	Method and Description
VarAdmin	admin()
Var	datatype(ResourceType.DataType<?> datatype)
Var	has(String type)
Var	has(String type, Object value) the variable must have a resource or name of the given type with an exact matching value
Var	has(String type, ValuePredicate predicate) the variable must have a resource or name of the given type that matches the given atom
Var	has(String type, Var var) the variable must have a resource or name of the given type that matches the given atom
Var	has(Var var)
Var	hasKey(String type)
Var	hasKey(Var type)
Var	hasResource(String type)
Var	hasResource(Var type)
Var	hasRole(String type)
Var	hasRole(Var type)
Var	hasScope(Var type)
Var	id(String id)
Var	isa(String type)
Var	isa(Var type)
Var	isAbstract() set this concept type variable as abstract, meaning it cannot have direct instances
Var	lhs(Pattern lhs)
Var	name(String name)
Var	neq(String varName) Specify that the variable is different to another variable
Var	neq(Var var) Specify that the variable is different to another variable
Var	playsRole(String type)
Var	playsRole(Var type)
Var	regex(String regex) Specify the regular expression instances of this resource type must match
Var	rel(String roleplayer) the variable must be a relation with the given roleplayer
Var	rel(String roletype, String roleplayer) the variable must be a relation with the given roleplayer playing the given roletype
Var	rel(String roletype, Var roleplayer) the variable must be a relation with the given roleplayer playing the given roletype
Var	rel(Var roleplayer) the variable must be a relation with the given roleplayer
Var	rel(Var roletype, String roleplayer) the variable must be a relation with the given roleplayer playing the given roletype
Var	rel(Var roletype, Var roleplayer) the variable must be a relation with the given roleplayer playing the given roletype
Var	rhs(Pattern rhs)
Var	sub(String type)
Var	sub(Var type)
Var	value() this variable must have a value
Var	value(Object value)
Var	value(ValuePredicate predicate)

Method Detail

id

Var id(String id)

Parameters:

id - a string that this variable's ID must match

Returns:

this

name

Var name(String name)

Parameters:

name - a string that this variable's name must match

Returns:

this

value

Var value()

this variable must have a value

Returns:

this

value

Var value(Object value)

Parameters:

value - a value that this variable's value must exactly match

Returns:

this

value

Var value(ValuePredicate predicate)

Parameters:

predicate - a atom this variable's value must match

Returns:

this

has

Var has(String type)

Parameters:

type - a resource type that this variable must have an instance of

Returns:

this

has

Var has(Var var)

Parameters:

var - a variable representing a resource

Returns:

this

has

Var has(String type,
        Object value)

the variable must have a resource or name of the given type with an exact matching value

Parameters:

type - a resource type in the ontology

value - a value of a resource

Returns:

this

has

Var has(String type,
        ValuePredicate predicate)

the variable must have a resource or name of the given type that matches the given atom

Parameters:

type - a resource type in the ontology

predicate - a atom on the value of a resource

Returns:

this

has

Var has(String type,
        Var var)

the variable must have a resource or name of the given type that matches the given atom

Parameters:

type - a resource type in the ontology

var - a variable representing a resource

Returns:

this

isa

Var isa(String type)

Parameters:

type - a concept type id that the variable must be of this type

Returns:

this

isa

Var isa(Var type)

Parameters:

type - a concept type that this variable must be an instance of

Returns:

this

sub

Var sub(String type)

Parameters:

type - a concept type id that this variable must be a kind of

Returns:

this

sub

Var sub(Var type)

Parameters:

type - a concept type that this variable must be a kind of

Returns:

this

hasRole

Var hasRole(String type)

Parameters:

type - a role type id that this relation type variable must have

Returns:

this

hasRole

Var hasRole(Var type)

Parameters:

type - a role type that this relation type variable must have

Returns:

this

playsRole

Var playsRole(String type)

Parameters:

type - a role type id that this concept type variable must play

Returns:

this

playsRole

Var playsRole(Var type)

Parameters:

type - a role type that this concept type variable must play

Returns:

this

hasScope

Var hasScope(Var type)

Parameters:

type - a scope that this variable must have

Returns:

this

hasResource

Var hasResource(String type)

Parameters:

type - a resource type that this type variable can be related to

Returns:

this

hasResource

Var hasResource(Var type)

Parameters:

type - a resource type that this type variable can be related to

Returns:

this

hasKey

Var hasKey(String type)

Parameters:

type - a resource type that this type variable can be one-to-one related to

Returns:

this

hasKey

Var hasKey(Var type)

Parameters:

type - a resource type that this type variable can be one-to-one related to

Returns:

this

rel

Var rel(String roleplayer)

the variable must be a relation with the given roleplayer

Parameters:

roleplayer - a variable representing a roleplayer

Returns:

this

rel

Var rel(Var roleplayer)

the variable must be a relation with the given roleplayer

Parameters:

roleplayer - a variable representing a roleplayer

Returns:

this

rel

Var rel(String roletype,
        String roleplayer)

the variable must be a relation with the given roleplayer playing the given roletype

Parameters:

roletype - a role type in the ontology

roleplayer - a variable representing a roleplayer

Returns:

this

rel

Var rel(Var roletype,
        String roleplayer)

the variable must be a relation with the given roleplayer playing the given roletype

Parameters:

roletype - a variable representing a roletype

roleplayer - a variable representing a roleplayer

Returns:

this

rel

Var rel(String roletype,
        Var roleplayer)

the variable must be a relation with the given roleplayer playing the given roletype

Parameters:

roletype - a role type in the ontology

roleplayer - a variable representing a roleplayer

Returns:

this

rel

Var rel(Var roletype,
        Var roleplayer)

the variable must be a relation with the given roleplayer playing the given roletype

Parameters:

roletype - a variable representing a roletype

roleplayer - a variable representing a roleplayer

Returns:

this

isAbstract

Var isAbstract()

set this concept type variable as abstract, meaning it cannot have direct instances

Returns:

this

datatype

Var datatype(ResourceType.DataType<?> datatype)

Parameters:

datatype - the datatype to set for this resource type variable

Returns:

this

regex

Var regex(String regex)

Specify the regular expression instances of this resource type must match

Parameters:

regex - the regex to set for this resource type variable

Returns:

this

lhs

Var lhs(Pattern lhs)

Parameters:

lhs - the left-hand side of this rule

Returns:

this

rhs

Var rhs(Pattern rhs)

Parameters:

rhs - the right-hand side of this rule

Returns:

this

neq

Var neq(String varName)

Specify that the variable is different to another variable

Parameters:

varName - the variable name that this variable should not be equal to

Returns:

this

neq

Var neq(Var var)

Specify that the variable is different to another variable

Parameters:

var - the variable that this variable should not be equal to

Returns:

this

admin

VarAdmin admin()

Specified by:

admin in interface Pattern

Returns:

an Admin class to allow inspection of this Var