RedisJSON と RedisGraph の基礎

Redis is incredibly versatile, but sometimes you need more specialized data handling. That's where Redis Modules come in!

These modules extend Redis's core functionality, allowing it to act as a document database, a graph database, and much more.

RedisJSON is a module that lets you store, update, and retrieve JSON documents directly within Redis. This is great for managing semi-structured data like user profiles, product catalogs, or configuration settings.

• Native JSON support: Store complex JSON objects.
• Atomic operations: Update parts of a JSON document efficiently.
• Powerful querying: Retrieve data using JSONPath expressions.

To store a JSON document, we use the JSON.SET command. You provide a key, a path (usually $ for the root), and the JSON string.

Try adding a simple user profile:

The JSON.GET command retrieves your JSON. You can get the entire document or specify a JSONPath to fetch only specific fields.

Let's get the full profile and then just Emma's name:

One of RedisJSON's strengths is updating specific parts of a document without fetching and rewriting the whole thing. Use JSON.SET with a precise path.

Update Emma's age and add a new hobby:

RedisGraph is another powerful module that turns Redis into a graph database. Graph databases are excellent for modeling relationships between data, like social networks, recommendation engines, or fraud detection.

Instead of tables, you work with nodes (entities) and edges (relationships).

In RedisGraph, you'll use Cypher, a declarative graph query language, to interact with your data.

• Nodes: Represent entities (e.g., Person, Product).
• Labels: Categorize nodes (e.g., :Person).
• Properties: Attributes of nodes/edges (e.g., name: 'Bob').
• Edges: Represent relationships (e.g., -[:FRIENDS_WITH]->).

The GRAPH.QUERY command lets you execute Cypher queries. Let's create a simple social graph with two people and a 'FRIENDS_WITH' relationship.

Notice the graph name 'social' is used to identify our graph.

You can query the graph to find patterns and relationships. The MATCH clause finds the pattern, and RETURN specifies what data to retrieve.

Find who Liam is friends with:

You have a RedisJSON document stored under the key product:details:123. The document looks like this:

{
  "name": "Wireless Earbuds",
  "specs": {
    "color": "Black",
    "battery_life": "8 hours",
    "features": ["Noise Cancelling", "Waterproof"]
  }
}

Which command correctly retrieves the 'Noise Cancelling' feature?

You've explored how RedisJSON enables efficient storage and manipulation of JSON documents using commands like JSON.SET and JSON.GET with JSONPath.

You also learned about RedisGraph, a powerful module for building and querying graph structures using Cypher, perfect for modeling relationships between data.

These modules significantly expand Redis's capabilities, letting it tackle a broader range of data modeling challenges!