Qdrant Vector Database – Cài đặt & Tìm kiếm ngữ nghĩa

import { QdrantClient } from '@qdrant/js-client-rest';

const client = new QdrantClient({ url: 'http://localhost:6333' });

// Tạo collection với vector 1536 chiều (OpenAI text-embedding-3-small)
await client.createCollection('documents', {
  vectors: {
    size: 1536,
    distance: 'Cosine',
  },
});

console.log('Collection created!');

import { v4 as uuidv4 } from 'uuid';
import OpenAI from 'openai';

const openai = new OpenAI({ apiKey: process.env.OPENAI_API_KEY });

async function embedText(text: string): Promise<number[]> {
  const res = await openai.embeddings.create({
    model: 'text-embedding-3-small',
    input: text,
  });
  return res.data[0].embedding;
}

async function insertDocuments(docs: Array<{ text: string; source: string }>) {
  const points = await Promise.all(
    docs.map(async (doc) => ({
      id: uuidv4(),
      vector: await embedText(doc.text),
      payload: {
        text: doc.text,
        source: doc.source,
        createdAt: new Date().toISOString(),
      },
    })),
  );

  await client.upsert('documents', {
    wait: true, // Đợi cho đến khi index xong
    points,
  });

  console.log(`Inserted ${points.length} points`);
}

// Sử dụng
await insertDocuments([
  { text: 'Chính sách hoàn tiền trong vòng 30 ngày kể từ ngày mua hàng', source: 'policy.pdf' },
  { text: 'Hướng dẫn đổi trả sản phẩm bị lỗi từ nhà sản xuất', source: 'policy.pdf' },
  { text: 'Thời gian giao hàng từ 2-5 ngày làm việc', source: 'faq.pdf' },
]);

async function search(query: string, topK = 5) {
  const queryVector = await embedText(query);

  const results = await client.search('documents', {
    vector: queryVector,
    limit: topK,
    with_payload: true, // Trả về payload (metadata)
  });

  return results.map(r => ({
    score: r.score,
    text: (r.payload as any).text,
    source: (r.payload as any).source,
  }));
}

// Sử dụng
const results = await search('Tôi muốn trả lại hàng');
results.forEach(r => {
  console.log(`Score: ${r.score.toFixed(3)} | ${r.text}`);
});
// Score: 0.891 | Chính sách hoàn tiền trong vòng 30 ngày...
// Score: 0.847 | Hướng dẫn đổi trả sản phẩm bị lỗi...

// Chỉ tìm trong tài liệu có source = 'policy.pdf'
const results = await client.search('documents', {
  vector: queryVector,
  limit: 5,
  with_payload: true,
  filter: {
    must: [
      { key: 'source', match: { value: 'policy.pdf' } },
    ],
  },
});

// Filter phức tạp hơn
const results2 = await client.search('documents', {
  vector: queryVector,
  limit: 5,
  filter: {
    must: [
      { key: 'category', match: { any: ['support', 'policy'] } },
      { key: 'language', match: { value: 'vi' } },
    ],
    must_not: [
      { key: 'isArchived', match: { value: true } },
    ],
  },
});

// Liệt kê tất cả collections
const collections = await client.getCollections();
console.log(collections.collections.map(c => c.name));

// Xem thông tin collection
const info = await client.getCollection('documents');
console.log(info.points_count); // Số lượng points

// Xóa points theo filter
await client.delete('documents', {
  filter: {
    must: [{ key: 'source', match: { value: 'old-doc.pdf' } }],
  },
});

// Xóa collection
await client.deleteCollection('documents');

import { Injectable, OnModuleInit } from '@nestjs/common';
import { QdrantClient } from '@qdrant/js-client-rest';

@Injectable()
export class QdrantService implements OnModuleInit {
  private client: QdrantClient;
  private readonly COLLECTION = 'documents';

  async onModuleInit() {
    this.client = new QdrantClient({ url: process.env.QDRANT_URL! });
    await this.ensureCollection();
  }

  private async ensureCollection() {
    const collections = await this.client.getCollections();
    const exists = collections.collections.some(c => c.name === this.COLLECTION);
    if (!exists) {
      await this.client.createCollection(this.COLLECTION, {
        vectors: { size: 1536, distance: 'Cosine' },
      });
    }
  }

  async upsert(points: Array<{ id: string; vector: number[]; payload: object }>) {
    await this.client.upsert(this.COLLECTION, { wait: true, points });
  }

  async search(vector: number[], topK = 5, filter?: object) {
    return this.client.search(this.COLLECTION, {
      vector,
      limit: topK,
      with_payload: true,
      ...(filter && { filter }),
    });
  }
}

const client = new QdrantClient({
  url: 'https://xxxx.us-east4-0.gcp.cloud.qdrant.io',
  apiKey: 'your-api-key',
});