Class VectorDBQAChain

Class that represents a VectorDBQAChain. It extends the BaseChain class and implements the VectorDBQAChainInput interface. It performs a similarity search using a vector store and combines the search results using a specified combine documents chain.

Deprecated

Switch to createRetrievalChain Will be removed in 0.2.0

Hierarchy (View Summary)

BaseChain
- VectorDBQAChain

Implements

VectorDBQAChainInput

Index

Constructors

constructor

new VectorDBQAChain(fields: VectorDBQAChainInput): VectorDBQAChain
Parameters
- fields: VectorDBQAChainInput
Returns VectorDBQAChain
Overrides BaseChain.constructor
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/vector_db_qa.ts:65

Properties

combineDocumentsChain

combineDocumentsChain: BaseChain

inputKey

inputKey: string = "query"

k

k: number = 4

`Optional`memory

memory?: any

returnSourceDocuments

returnSourceDocuments: boolean = false

vectorstore

vectorstore: VectorStoreInterface

Accessors

inputKeys

get inputKeys(): string[]
Returns string[]
Overrides BaseChain.inputKeys
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/vector_db_qa.ts:49

lc_namespace

get lc_namespace(): string[]
Returns string[]
Inherited from QAEvalChain.lc_namespace
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/base.ts:41

outputKeys

get outputKeys(): string[]
Returns string[]
Overrides BaseChain.outputKeys
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/vector_db_qa.ts:53

Methods

_chainType

_chainType(): "vector_db_qa"
Return the string type key uniquely identifying this class of chain.

Returns "vector_db_qa"
Overrides BaseChain._chainType
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/vector_db_qa.ts:104

`Protected`_formatValues

_formatValues(values: any): Promise<any>
Parameters
- values: any
Returns Promise<any>
Inherited from BaseChain._formatValues
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/base.ts:217

apply

apply(inputs: ChainValues[], config?: any[]): Promise<ChainValues[]>
Parameters
- inputs: ChainValues[]
- Optionalconfig: any[]
Returns Promise<ChainValues[]>
Deprecated
Use .batch() instead. Will be removed in 0.2.0.

Call the chain on all inputs in the list
Inherited from BaseChain.apply
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/base.ts:258

call

call(values: any, config?: any, tags?: string[]): Promise<ChainValues>
Parameters
- values: any
- Optionalconfig: any
- Optionaltags: string[]
  Deprecated
Returns Promise<ChainValues>
Deprecated
Use .invoke() instead. Will be removed in 0.2.0.

Run the core logic of this chain and add to output if desired.

Wraps _call and handles memory.
Inherited from BaseChain.call
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/base.ts:243

invoke

invoke(input: ChainValues, options?: any): Promise<ChainValues>
Invoke the chain with the provided input and returns the output.
Parameters
- input: ChainValues
  Input values for the chain run.
- Optionaloptions: any
Returns Promise<ChainValues>
Promise that resolves with the output of the chain run.
Inherited from BaseChain.invoke
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/base.ts:86

prepOutputs

prepOutputs(
    inputs: Record<string, unknown>,
    outputs: Record<string, unknown>,
    returnOnlyOutputs?: boolean,
): Promise<Record<string, unknown>>
Parameters
- inputs: Record<string, unknown>
- outputs: Record<string, unknown>
- returnOnlyOutputs: boolean = false
Returns Promise<Record<string, unknown>>
Inherited from BaseChain.prepOutputs
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/base.ts:149

run

run(input: any, config?: any): Promise<string>
Parameters
- input: any
- Optionalconfig: any
Returns Promise<string>
Deprecated
Use .invoke() instead. Will be removed in 0.2.0.
Inherited from BaseChain.run
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/base.ts:190

serialize

serialize(): SerializedVectorDBQAChain
Return a json-like object representing this chain.

Returns SerializedVectorDBQAChain
Overrides BaseChain.serialize
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/vector_db_qa.ts:133

`Static`deserialize

deserialize(
data: SerializedVectorDBQAChain,
values: LoadValues,
): Promise<VectorDBQAChain>
Load a chain from a json-like object describing it.
Parameters
- data: SerializedVectorDBQAChain
- values: LoadValues
Returns Promise<VectorDBQAChain>
Overrides BaseChain.deserialize
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/vector_db_qa.ts:108

`Static`fromLLM

fromLLM(
    llm: BaseLanguageModelInterface,
    vectorstore: VectorStoreInterface,
    options?: Partial<
        Omit<VectorDBQAChainInput, "vectorstore" | "combineDocumentsChain">,
    >,
): VectorDBQAChain
Static method that creates a VectorDBQAChain instance from a BaseLanguageModel and a vector store. It also accepts optional options to customize the chain.
Parameters
- llm: BaseLanguageModelInterface
  The BaseLanguageModel instance.
- vectorstore: VectorStoreInterface
  The vector store used for similarity search.
- Optionaloptions: Partial<Omit<VectorDBQAChainInput, "vectorstore" | "combineDocumentsChain">>
  Optional options to customize the chain.
Returns VectorDBQAChain
A new instance of VectorDBQAChain.
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/vector_db_qa.ts:150

`Static`lc_name

lc_name(): string
Returns string
- Defined in remotes/langchain-ai/langchainjs/v1/libs/langchain/src/chains/vector_db_qa.ts:41

Class VectorDBQAChain

Deprecated

Hierarchy (View Summary)

Implements

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Parameters

Returns VectorDBQAChain

Properties

combineDocumentsChain

inputKey

k

Optionalmemory

returnSourceDocuments

vectorstore

Accessors

inputKeys

Returns string[]

lc_namespace

Returns string[]

outputKeys

Returns string[]

Methods

_chainType

Returns "vector_db_qa"

Protected_formatValues

Parameters

Returns Promise<any>

apply

Parameters

Returns Promise<ChainValues[]>

Deprecated

call

Parameters

Deprecated

Returns Promise<ChainValues>

Deprecated

invoke

Parameters

Returns Promise<ChainValues>

prepOutputs

Parameters

Returns Promise<Record<string, unknown>>

run

Parameters

Returns Promise<string>

Deprecated

serialize

Returns SerializedVectorDBQAChain

Staticdeserialize

Parameters

Returns Promise<VectorDBQAChain>

StaticfromLLM

Parameters

Returns VectorDBQAChain

Staticlc_name

Returns string

Settings

On This Page

`Optional`memory

`Protected`_formatValues

`Static`deserialize

`Static`fromLLM

`Static`lc_name