Node. js uses the redis database to cache data

The Redis database adopts a simple design concept. The latest source code package is less than 2 Mb. Its usage is also different from the general database. The following article introduces how node. js uses the redis database to cache data. If you need it, let's take a look at it. The Redis database adopts a simple design concept. The latest source code package is less than 2 Mb. Its usage is also different from the general database. The following article introduces how node. js uses the redis database to cache data. If you need it, let's take a look at it.

I. Run redis

The Redis server uses port 6379 by default.

redis-server

Custom Port

redis-server –port 6390

Client

redis-cli

Specify ip address and port connection

redis-cli -h 127.0.0.1 -p 6390

Test whether the client and server are connected.

Ping

Ii. Nodejs connection to redis

Passredis.createClient(port,host,options)To connect to the redis Server

var redis = require("redis")var client = redis.createClient();

/* Client. HMSET stores the hash key value */client. HMSET (key, val, function (err, result) {if (err) {return callback ({code: 0, msg: err});} callback ({code: 1, msg: result});/* set the expiration time to 1 day */client. EXPIRE (bottleId, 86400 );});

/* Return a random key of the current database */client. RANDOMKEY (function (err, key) {if (! Key) {return callback ({code: 0, msg: 'No data'});}/* return the hash object based on the key */client. HGETALL (key, function (err, val) {if (err) {return callback ({code: 0, msg: err});} callback ({code: 1, msg: val});/* Delete the key value based on the key */client. DEL (key );});});

Iii. Common Redis commands

Redis command reference manual

Clear Database

FLUSHALL

Delete key

DEL key

Check whether the key exists.

EXISTS key // string HEXISTS key field // check whether the specified field EXISTS in the hash table key.

Return the type of the value stored in the key.

TYPE key

Obtains the value stored by the key.

String

GET key

Hash

HGETALL key // obtain all fields and values of the specified key in the hash table

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