查询资料才发现：Node Redis版本V4之后，连接语法变了。
Starting from v4 of node-redis library, you need to call client.connect() after initializing a client. See this migration guide.
新语法：
const redis = require('redis')
const client = redis.createClient({ socket: { port: 6379 } })
client.connect()
client.on('connect', () =>{
console.log('connected')
})
You might also want to consider running the client connect method with await in an asynchronous function. So you don't have to worry about event listeners.
const redis = require('redis')
(async () =>{
try {
const client = redis.createClient({ socket: { port: 6379 } })
await client.connect()
console.log('connected')
} catch (err) {
console.error(err)
}
})()
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
[Example]:
const redis = require("redis")
(async () =>{
try {
const client = redis.createClient({
socket: { port: 6379 },
legacyMode: true,
})
await client.connect()
console.log("connected")
await client.v4.set("key4", "value2", {
NX: true,
})
client.set("key3", "value3", "NX", (err, reply) =>{})
await client.get("key4", function (err, v) {
console.log("redis get hello err,v", err, v)
})
client.set("student1", "Laylaa1", function (err, reply) {
if (err) {
console.log(err)
callback(err, null)
return
}
console.log(reply)
})
} catch (err) {
console.error(err)
}
})()
在java下可以使用 :String value = redis.get(key)
是同步的
但在nodejs 下使用：
```javascript
var value
var isConnection = client.get(key,function(err,repy){
value = repy
client.quit()//调用了quit之后isConnection就是false了，这个get方法应该是返回连接状态吧？
})
client.get直接返回的结果是！client.shou_buffer。而且对于异步操作的js，这个值肯定是它向redis发送请求之前就被返回了的。
