0Pricing
Vector Databases: Pinecone, Weaviate & pgvector · レッスン

Weaviate GraphQLクエリ

強力なGraphQL APIを使ってWeaviateのデータをクエリし、セマンティック検索やデータ取得を行う方法を習得します。

「Weaviate GraphQLクエリ」はCoddyKit上の無料Vector Databases: Pinecone, Weaviate & pgvectorレッスンです。 これはレッスン3/4です。 下記で完全なレッスンを無料で読むことができます。その後、ブラウザ内の組み込みコードエディタと24時間対応のAIチューターでハンズオン演習できます。 これはVector Databases: Pinecone, Weaviate & pgvector学習パスの一部であり、ウェブとCoddyKitアプリ全体で進捗が同期されます。 Vector Databases: Pinecone, Weaviate & pgvectorコースには全4レッスンが含まれています。

このレッスンの一部はまだ翻訳されておらず、英語で表示されています。

Weaviate's GraphQL Power

Welcome! In this lesson, you'll master querying your Weaviate data. Weaviate uses GraphQL, a powerful query language, for flexible and efficient data retrieval.

GraphQL allows you to request exactly the data you need, nothing more, nothing less. This is especially useful for complex searches, including vector similarity.

Basic Data Retrieval: Get

The foundation of querying in Weaviate is the Get operation. It allows you to fetch data objects from a specific class defined in your schema.

  • Specify the class name (e.g., Article).
  • Select the properties you want to retrieve (e.g., title, content).
  • Weaviate will return all objects of that class with the specified properties.

Get All Objects Example

Let's see a basic Get query in action. This Python code connects to your Weaviate instance and fetches the title and content of all Article objects.

(Ensure you have a Weaviate instance running locally at http://localhost:8080 and an 'Article' class with some data.)

import weaviate

# Connect to your Weaviate instance
# For local: http://localhost:8080
client = weaviate.Client(url="http://localhost:8080")

# Perform a basic Get query for 'Article' objects
try:
    response = client.query.get("Article", ["title", "content"]).do()
    print("--- Retrieved Articles ---")
    for article in response["data"]["Get"]["Article"]:
        print(f"Title: {article['title']}")
except Exception as e:
    print(f"Error during query: {e}")

Filtering Data with 'where'

Often, you don't want all objects, but specific ones. The where filter allows you to add conditions to your queries, narrowing down the results.

  • You can filter by property values (text, number, boolean, date).
  • Use operators like Equal, Like, GreaterThan, etc.
  • Combine multiple conditions with _and or _or clauses.

Filter by Property Value

This example shows how to use the where filter to find articles written by a specific author. We'll look for articles where the author property matches 'Jane Doe'.

import weaviate

client = weaviate.Client(url="http://localhost:8080")

# Define the 'where' filter
where_filter = {
    "path": ["author"],
    "operator": "Equal",
    "valueText": "Jane Doe"
}

# Perform the Get query with the filter
try:
    response = client.query.get("Article", ["title", "author"])
                          .with_where(where_filter).do()
    print("--- Articles by Jane Doe ---")
    for article in response["data"]["Get"]["Article"]:
        print(f"Title: {article['title']}, Author: {article['author']}")
except Exception as e:
    print(f"Error during query: {e}")

Retrieving Vector Embeddings

Weaviate stores a vector embedding for each object, representing its semantic meaning. You can retrieve this vector directly as part of your GraphQL query.

To do this, you use the _additional { vector } clause. This is useful for debugging, understanding your data, or performing custom operations outside Weaviate.

Get Vector Embedding

Here's how to fetch the vector embedding along with other properties. We'll get the title and the vector for the first article found.

import weaviate

client = weaviate.Client(url="http://localhost:8080")

# Query for a title and its vector
try:
    response = client.query.get("Article", ["title"])
                          .with_additional("vector")
                          .with_limit(1).do()
    print("--- Article Title and Vector ---")
    if response["data"]["Get"]["Article"]:
        article = response["data"]["Get"]["Article"][0]
        print(f"Title: {article['title']}")
        print(f"Vector (first 5 elements): {article['_additional']['vector'][:5]}...")
    else:
        print("No articles found.")
except Exception as e:
    print(f"Error during query: {e}")

Powerful Semantic Search

One of Weaviate's core strengths is semantic search. Instead of keyword matching, it finds data objects based on their meaning, even if the exact words aren't present.

This is achieved using the nearText operator. You provide 'concepts' (text) and Weaviate uses them to find the most semantically similar objects in your database.

Find Similar Articles

Let's perform a semantic search to find articles related to 'machine learning applications'. Notice how we use with_near_text and provide our query concepts.

import weaviate

client = weaviate.Client(url="http://localhost:8080")

# Define the concepts for semantic search
concepts = ["machine learning applications"]

# Perform a nearText query
try:
    response = client.query.get("Article", ["title", "content"])
                          .with_near_text({"concepts": concepts})
                          .with_limit(3).do()
    print("--- Articles similar to 'machine learning applications' ---")
    for article in response["data"]["Get"]["Article"]:
        print(f"Title: {article['title']}")
except Exception as e:
    print(f"Error during query: {e}")

GraphQL Query Challenge

You've learned about various ways to query data in Weaviate using GraphQL.

Which of the following GraphQL query operations is specifically used to find data objects that are semantically similar to a given text concept?

Weaviate Queries Recap

Great job! You've mastered the essentials of Weaviate's powerful GraphQL API:

  • The Get operation retrieves data objects and their properties.
  • The where filter allows you to apply precise conditions to your searches.
  • You can explicitly fetch an object's vector embedding using _additional { vector }.
  • The nearText operator powers semantic search, finding items based on meaning.

These tools enable you to efficiently retrieve and explore your vector data in Weaviate!

よくある質問

「Weaviate GraphQLクエリ」レッスンは無料ですか？

はい。「Weaviate GraphQLクエリ」の完全なテキストはこのウェブで無料で読めます。インタラクティブに演習し（組み込みコードエディタと24時間対応のAIチューター）、Vector Databases: Pinecone, Weaviate & pgvectorコースの残りをアンロックするには、CoddyKit PROにアップグレードしてください。 Vector Databases: Pinecone, Weaviate & pgvectorコースには全4レッスンが含まれています。

「Weaviate GraphQLクエリ」で何を学びますか？

強力なGraphQL APIを使ってWeaviateのデータをクエリし、セマンティック検索やデータ取得を行う方法を習得します。 ブラウザで直接実行するハンズオンコードでVector Databases: Pinecone, Weaviate & pgvectorを演習し、24時間対応のAIチューターがレッスンを進める中での質問に答えます。

Vector Databases: Pinecone, Weaviate & pgvectorを始めるのに経験は必要ですか？

事前経験は必要ありません。CoddyKitのVector Databases: Pinecone, Weaviate & pgvectorは初級者から上級者向けに構成されているため、ここから始めるか最初から始めて、自分のペースで進むことができます。 これはレッスン3/4です。

「Weaviate GraphQLクエリ」レッスンにはどのくらい時間がかかりますか？

ほとんどのCoddyKitレッスンは約5～10分かかります。各レッスンはコンパクトでインタラクティブなので、着実に進歩し、ウェブとアプリ全体で正確に前回の場所から再開できます。

このVector Databases: Pinecone, Weaviate & pgvectorレッスンでコードを書いて実行できますか？

はい。すべてのVector Databases: Pinecone, Weaviate & pgvectorレッスンに組み込みコードエディタが含まれているため、ブラウザでリアルコードを書いて実行し、即座のAIフィードバックを取得できます。ローカル設定は不要です。

このコースのすべてのレッスン

  1. Weaviateスキーマの定義
  2. データオブジェクトのインポート
  3. Weaviate GraphQLクエリ
  4. Vectorizerモジュールと自動Embedding
← Vector Databases: Pinecone, Weaviate & pgvectorに戻る