👐 Add Semantic Search to Your Application

You now know everything you need to add vector search capabilities to your application.

🚀 NodeJS/Express

Open up the BookController in server/src/controllers/books.ts once more, and edit the searchBooks method to query your data for semantic search.

tip

Use the getEmbeddings function to convert the query into a vector.

Answer

public async searchBooks(query: string): Promise<Book[]> {
  const vector = await getEmbeddings(query);
  const aggregationPipeline = [
    {
      $vectorSearch: {
        queryVector:  vector,
        path: 'embeddings',
        numCandidates: 100,
        index: 'vectorsearch',
        limit: 10,
      }
    }
  ];
  const books = await collections?.books?.aggregate(aggregationPipeline).toArray() as Book[];
  return books;
}

☕️ Java Spring Boot

Open the BookService class in /domain/service/BookService.java, locate the searchBooks(String theTerm) method, and update it to use Vector Search for semantic queries.

tip

Use the embeddingProvider.getEmbeddings method to convert the query into a vector.

Answer

src/main/java/com/mongodb/devrel/library/domain/service/BookService.java

public List<Book> searchBooks(String theTerm) {
    List<Double> vector = embeddingProvider.getEmbeddings(theTerm);

    AggregationOperation searchStage = context ->
            new Document("$vectorSearch",
                    new Document("index", "vectorsearch")
                            .append("path", "embeddings")
                            .append("queryVector", vector)
                            .append("numCandidates", 100)
                            .append("limit", 10)
     );

    Aggregation aggregation = Aggregation.newAggregation(searchStage);
    return mongoTemplate.aggregate(aggregation, "books", Book.class).getMappedResults();
}

Testing the semantic search

To test the semantic search in the app, try to search for some books but use different words that have a similar meaning or are related to the book's cover.

You can use the following queries:

• Canines doing stuff
• Fluffy animals
• European history