先从Redis查，有没有就别往数据库走了（先去redis再去数据库）

As a developer, managing the data we store in databases can be a hassle. Much of this comes from the fact that querying databases can be slow, making it difficult to serve requests quickly. In order to overcome this and provide faster access to data, many developers are turning to Redis for their caching needs.

Redis is an in-memory data structure store that can store data in a variety of formats such as strings, hashes, lists, sets and more. Redis is often used as the primary data store for caching data, as it is extremely fast and provides easy retrieval.

One way to use Redis to speed up data access is to query the data in Redis before making a request to the database. The idea here is that we can first try to find the data in Redis and if it exists, we can use that data instead of querying the database. This saves time and allows us to serve requests more quickly.

To illustrate this concept, let’s take a look at some sample code. Suppose we have a user object that we need to query the database for. We can first query Redis to see if the user exists there and if it does, we can simply return the data from Redis.

// Try to get the user from Redis

let user = redis.get(‘user’);

// If not found, query the database

if (!user) {

user = awt DB.query(‘SELECT * FROM users WHERE id = ?’, [1]);

redis.set(‘user’, user);

}

// Return the user object from either the Redis store or the database

return user;

In the above example, we first try to query for the user in Redis and if it’s not found, we then query the database. This way, we minimize the number of queries to the database, making it faster and easier to serve requests.

By using Redis to cache our data, we can reduce the number of queries to the database, resulting in faster response times and improved performance. Redis is easy to setup and provides an easy way to improve data access speeds and performance.