自我查询色度检索器

自我查询检索器正如其名称所示具有查询自身的能力。具体而言给定任何自然语言查询检索器使用查询构建LLM链来撰写结构化查询，然后将该结构化查询应用于其基础向量存储中。这使得检索器不仅可以使用用户输入的查询进行与存储文档内容的语义相似性比较，而且可以从用户查询中提取存储文档的元数据过滤器并执行这些过滤器。

此示例使用Chroma向量存储。

用法

此示例演示如何使用向量存储初始化SelfQueryRetriever :

import { AttributeInfo } from "langchain/schema/query_constructor";
import { Document } from "langchain/document";
import { OpenAIEmbeddings } from "langchain/embeddings/openai";
import {
  SelfQueryRetriever,
  BasicTranslator,
} from "langchain/retrievers/self_query";
import { OpenAI } from "langchain/llms/openai";
import { Chroma } from "langchain/vectorstores/chroma";

/**
 * First, we create a bunch of documents. You can load your own documents here instead.
 * Each document has a pageContent and a metadata field. Make sure your metadata matches the AttributeInfo below.
 */
const docs = [
  new Document({
    pageContent:
      "A bunch of scientists bring back dinosaurs and mayhem breaks loose",
    metadata: { year: 1993, rating: 7.7, genre: "science fiction" },
  }),
  new Document({
    pageContent:
      "Leo DiCaprio gets lost in a dream within a dream within a dream within a ...",
    metadata: { year: 2010, director: "Christopher Nolan", rating: 8.2 },
  }),
  new Document({
    pageContent:
      "A psychologist / detective gets lost in a series of dreams within dreams within dreams and Inception reused the idea",
    metadata: { year: 2006, director: "Satoshi Kon", rating: 8.6 },
  }),
  new Document({
    pageContent:
      "A bunch of normal-sized women are supremely wholesome and some men pine after them",
    metadata: { year: 2019, director: "Greta Gerwig", rating: 8.3 },
  }),
  new Document({
    pageContent: "Toys come alive and have a blast doing so",
    metadata: { year: 1995, genre: "animated" },
  }),
  new Document({
    pageContent: "Three men walk into the Zone, three men walk out of the Zone",
    metadata: {
      year: 1979,
      director: "Andrei Tarkovsky",
      genre: "science fiction",
      rating: 9.9,
    },
  }),
];

/**
 * Next, we define the attributes we want to be able to query on.
 * in this case, we want to be able to query on the genre, year, director, rating, and length of the movie.
 * We also provide a description of each attribute and the type of the attribute.
 * This is used to generate the query prompts.
 */
const attributeInfo: AttributeInfo[] = [
  {
    name: "genre",
    description: "The genre of the movie",
    type: "string or array of strings",
  },
  {
    name: "year",
    description: "The year the movie was released",
    type: "number",
  },
  {
    name: "director",
    description: "The director of the movie",
    type: "string",
  },
  {
    name: "rating",
    description: "The rating of the movie (1-10)",
    type: "number",
  },
  {
    name: "length",
    description: "The length of the movie in minutes",
    type: "number",
  },
];

/**
 * Next, we instantiate a vector store. This is where we store the embeddings of the documents.
 * We use the Pinecone vector store here, but you can use any vector store you want.
 * At this point we only support Chroma and Pinecone, but we will add more in the future.
 * We also need to provide an embeddings object. This is used to embed the documents.
 */
const embeddings = new OpenAIEmbeddings();
const llm = new OpenAI();
const documentContents = "Brief summary of a movie";
const vectorStore = await Chroma.fromDocuments(docs, embeddings, {
  collectionName: "a-movie-collection",
});
const selfQueryRetriever = await SelfQueryRetriever.fromLLM({
  llm,
  vectorStore,
  documentContents,
  attributeInfo,
  /**
   * We need to create a basic translator that translates the queries into a
   * filter format that the vector store can understand. We provide a basic translator
   * translator here (which works for Chroma and Pinecone), but you can create
   * your own translator by extending BaseTranslator abstract class. Note that the
   * vector store needs to support filtering on the metadata attributes you want to
   * query on.
   */
  structuredQueryTranslator: new BasicTranslator(),
});

/**
 * Now we can query the vector store.
 * We can ask questions like "Which movies are less than 90 minutes?" or "Which movies are rated higher than 8.5?".
 * We can also ask questions like "Which movies are either comedy or drama and are less than 90 minutes?".
 * The retriever will automatically convert these questions into queries that can be used to retrieve documents.
 */
const query1 = await selfQueryRetriever.getRelevantDocuments(
  "Which movies are less than 90 minutes?"
);
const query2 = await selfQueryRetriever.getRelevantDocuments(
  "Which movies are rated higher than 8.5?"
);
const query3 = await selfQueryRetriever.getRelevantDocuments(
  "Which movies are directed by Greta Gerwig?"
);
const query4 = await selfQueryRetriever.getRelevantDocuments(
  "Which movies are either comedy or drama and are less than 90 minutes?"
);
console.log(query1, query2, query3, query4);