Class: NullSource

Defined in: packages/core/src/plan/operators/null-source.ts:9

A leaf operator that emits exactly one empty row with no attributes.

Used as the source for queries that have no FROM clause (e.g. SELECT 1).

Extends

• PlanTupleOperator

Constructors

Constructor

new NullSource(lang): NullSource

Defined in: packages/core/src/plan/operators/null-source.ts:10

Parameters

Parameter	Type
lang	Lowercase<string>

Returns

NullSource

Overrides

PlanTupleOperator.constructor

Properties

lang

lang: Lowercase<string>

Defined in: packages/core/src/plan/visitor.ts:42

PlanOperator.lang

Inherited from

PlanTupleOperator.lang

---

parent?

optional parent?: PlanOperator

Defined in: packages/core/src/plan/visitor.ts:44

PlanOperator.parent

Inherited from

PlanTupleOperator.parent

---

schema

schema: ASTIdentifier[]

Defined in: packages/core/src/plan/visitor.ts:38

Ordered list of attribute identifiers produced by this operator.

Inherited from

PlanTupleOperator.schema

---

schemaSet

schemaSet: IdSet

Defined in: packages/core/src/plan/visitor.ts:40

Trie-backed set of the same paths as schema; used for O(k) membership tests.

Inherited from

PlanTupleOperator.schemaSet

Methods

accept()

accept<Ret, Arg>(visitors, arg?): Ret

Defined in: packages/core/src/plan/operators/null-source.ts:18

PlanOperator.accept

Type Parameters

Type Parameter
Ret
Arg

Parameters

Parameter	Type
visitors	Record<string, PlanVisitor<Ret, Arg>>
arg?	Arg

Returns

Ret

Overrides

PlanTupleOperator.accept

---

addToSchema()

addToSchema(item): void

Defined in: packages/core/src/plan/visitor.ts:57

will preserve object references

Parameters

Parameter	Type
item	IdSet | ASTIdentifier | ASTIdentifier[]

Returns

void

Inherited from

PlanTupleOperator.addToSchema

---

clearSchema()

clearSchema(): void

Defined in: packages/core/src/plan/visitor.ts:102

will preserve object references

Returns

void

Inherited from

PlanTupleOperator.clearSchema

---

clone()

clone(): NullSource

Defined in: packages/core/src/plan/operators/null-source.ts:33

PlanOperator.clone

Returns

NullSource

Overrides

PlanTupleOperator.clone

---

getChildren()

getChildren(): PlanOperator[]

Defined in: packages/core/src/plan/operators/null-source.ts:29

PlanOperator.getChildren

Returns

PlanOperator[]

Overrides

PlanTupleOperator.getChildren

---

getDependencies()

getDependencies(): IdSet

Defined in: packages/core/src/plan/visitor.ts:113

PlanOperator.getDependencies

Returns

IdSet

Inherited from

PlanTupleOperator.getDependencies

---

removeFromSchema()

removeFromSchema(item): boolean

Defined in: packages/core/src/plan/visitor.ts:80

will preserve object references

Parameters

Parameter	Type
item	IdSet | ASTIdentifier | ASTIdentifier[]

Returns

boolean

Inherited from

PlanTupleOperator.removeFromSchema

---

replaceChild()

replaceChild(current, replacement): void

Defined in: packages/core/src/plan/operators/null-source.ts:25

PlanOperator.replaceChild

Parameters

Parameter	Type
current	PlanOperator
replacement	PlanOperator

Returns

void

Overrides

PlanTupleOperator.replaceChild