vinayak

Posted on Jun 5, 2022 • Originally published at itsvinayak.hashnode.dev on Jun 5, 2022

Basic Operations with node_redis

#node #redis #javascript #programming

node_redis

node_redis is a modern, high-performance Redis client for Node.js. It has over 3,658,902 Weekly Downloads and has in-build support for all Redis commands. it uses the raw Redis command with all capital letters as well as a camel-cased version of these commands.

Examples:

// Redis commands syntex
await client.SET('key', 'field', 'value');
await client.GET('key');


// camel cased commands
await client.rPush('key', 'value');
await client.lRange('key', from, to);

Installing node_redis in Javascript

npm i redis

Javascript Datatype Mapping with Redis Type

Javascript Datatype	Redis Type
String	string
Array of String	list
Array of String	set
Integer	number
String	float
Object	hash

Redis Command Using node_redis

Hash Commands

HSET: Sets the string value of a hash field.

Redis Example

HSET id key "value"

Output

OK

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.HSET('id', 'key', 'value').then((res) => {
  console.log('Set key value : ', res);
  client.quit();
});

Output

Redis Client Connected
Set key value : 0

HGET: Gets the value of a hash field stored at the specified key.

Redis Example

HGET id key

Output

value

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.get('key').then((res) => {
  console.log('Get key value : ', res);
  client.quit();
});

Output

Redis Client Connected
Get key value : value

HMGET: Gets the values of all the given hash fields.

Redis Example

HMGET id key1 key2

Output

1) "value"
2) "value1"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.HMGET('id', ['key1', 'key2']).then((res) => {
  console.log('Get key value : ', res);
  client.quit();
});

Output

Redis Client Connected
Get key value : ['hello', 'world']

HMSET: Sets multiple hash fields to multiple values.

Redis Example

HMSET id key1 "Hello" key2 "World"

Output

OK

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();
client.HSET('id', ['key1', 'hello', 'key2', 'world']).then((res) => {
  console.log('Set key value : ', res);
  client.quit();
});

Output

Redis Client Connected
Set key value : 1

HDEL: Deletes one or more hash fields.

Redis Example

HDEL id key1

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.HDEL('id', 'key1').then((res) => {
  console.log('Deleted key1 : ', res);
});

Output

Redis Client Connected
Deleted key1 : 1

HEXISTS: Determines whether a hash field exists or not.

Redis Example

HEXISTS id key1

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.HEXISTS('id', 'key1').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
false

HGETALL: Gets all the fields and values Stored in a hash.

Redis Example

HGETALL id key1

Output

 1) "key"
 2) "value"
 3) "key2"
 4) "world"
 5) "numkey"
 6) "10"
 7) "floatkey"
 8) "10.2"
 9) "key1"
10) "value1"
11) "key11"
12) "value1"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.HGETALL('id').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
[Object: null prototype] { key: 'value', key2: 'world' }

HINCRBY: Increments the integer value of a hash field by the given number.

Redis Example

HINCRBY id numkey 3

Output

6


HINCRBY id numkey 3

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.HSET('id', 'numkey', 9).then((res) => {
  console.log('set numkey', res);
});

client.HINCRBY('id', 'numkey', 1).then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
set numkey 1
10

HINCRBYFLOAT: Increments the float value of a hash field by the given amount.

Redis Example

HINCRBYFLOAT id floatkey 0.5

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.HSET('id', 'floatkey', 9.1).then((res) => {
  console.log('set floatkey', res);
});

client.HINCRBYFLOAT('id', 'floatkey', 1.1).then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
set floatkey 1
10.2

HKEYS: Gets all the fields in a hash.

Redis Example

HKEYS id

Output

1) "key"
2) "key2"
3) "numkey"
4) "floatkey"
5) "key1"
6) "key11"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.HKEYS('id').then((keys) => {
  console.log(keys);
  client.quit();
});

Output

Redis Client Connected
['key', 'key2', 'numkey', 'floatkey', 'key1', 'key11']

HLEN: Gets the number of fields in a hash.

Redis Example

HLEN id

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.HLEN('id').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
4

HSETNX: Sets the value of a hash field, only if the field does not exist.

Redis Example

HSETNX id key1 value1

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.HSETNX('id', 'key1', 'value1').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
true

HVALS: Gets all the values in a hash

Redis Example

HVALS id

Output

1) "value"
2) "world"
3) "10"
4) "10.2"
5) "value1"
6) "value1"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.HVALS('id').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
['value', 'world', '10', '10.2', 'value1', 'value1']

HSCAN: Incrementally iterates hash fields and associated values.

Redis Example

HSCAN id curser


HSCAN id 0

Output

1) "0"
2) 1) "key"
    2) "value"
    3) "key2"
    4) "world"
    5) "numkey"
    6) "10"
    7) "floatkey"
    8) "10.2"
    9) "key1"
   10) "value1"
   11) "key11"
   12) "value1"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.HSCAN('id', 0).then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
{
  cursor: 0,
  tuples: [
    { field: 'key', value: 'value' },
    { field: 'key2', value: 'world' },
    { field: 'numkey', value: '10' },
    { field: 'floatkey', value: '10.2' },
    { field: 'key1', value: 'value1' },
    { field: 'key11', value: 'value1' }
  ]
}

List commands

BLPOP: It is the blocking version of LPOP as it Removes and gets the first element in a list, or blocks until one is available

Redis Example

 BLPOP list1 list2 timeout

Output

1) "list1"
2) "a"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.BLPOP('mylist', 2).then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
{ key: 'mylist', element: 'three' }

BRPOP: Removes and gets the last element in a list, or blocks until one is available

Redis Example

BRPOP list1 list2 timeout

Output

1) "list1"
2) "hello"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.BRPOP('mylist', 1).then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
null

LINDEX: Gets an element from a list by its index

Redis Example

LINDEX mylist position


LINDEX mylist 0

Output

"hello"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.LINDEX('mylist', 0).then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
nice

LINSERT: Insert an element before or after another element in a list

Redis Example

LINSERT mylist BEFORE "World" "There"

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.LINSERT('mylist', 'BEFORE', 'nice', 'three').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
4

LLEN: Gets the length of a list

Redis Example

LLEN mylist

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.LLEN('mylist').then((length) => {
  console.log(length);
  client.quit();
});

Output

Redis Client Connected
4

LPOP: Removes and gets the first element in a list

Redis Example

LPOP mylist

Output

"three"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.LPOP('mylist').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
nice

LPUSH: Prepends one or multiple values to a list

Redis Example

LPUSH mylist "hello"

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.LPUSH('mylist', 'one').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
3

LPUSHX: Prepends a value to a list, only if the list exists

Redis Example

LPUSHX mylist "Hello"

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.LPUSHX('mylist', 'value1').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
4

LRANGE: Gets a range of elements from a list

Redis Example

LRANGE mylist -3 2

Output

1) "one"
2) "two"
3) "three"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.LRANGE('mylist', 0, -1).then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
['value1', 'one', 'world', 'hello']

LREM: Removes elements from a list

Redis Example

LREM mylist -2 "hello"

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.LREM('mylist', 0, 'hello').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
1

LSET: Sets the value of an element in a list by its index

Redis Example

LSET mylist 0 "four"

Output

OK

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.LSET('mylist', 0, 'Hello').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
OK

LTRIM: Trims a list to the specified range

Redis Example

 LTRIM mylist 1 -1

Output

OK

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.LTRIM('mylist', 1, -1).then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
OK

RPOP: Removes and gets the last element in a list

Redis Example

 RPOP mylist

Output

hello

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.RPOP('mylist').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
hello

RPOPLPUSH: Removes the last element in a list, appends it to another list, and returns it

Redis Example

 RPOPLPUSH mylist myotherlist

Output

world

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.RPOPLPUSH('mylist', 'myotherlist').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
world

RPUSH: Appends one or multiple values to a list

Redis Example

RPUSH mylist "hello"

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.RPUSH('mylist', 'hello').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
1

RPUSHX: Appends a value to a list, only if the list exists and returns the length of the list

Redis Example

RPUSHX mylist "world"

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.RPUSHX('mylist', 'world').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
2

Set Commands

SADD: Adds one or more members to a set

Redis Example

SADD myset "Hello"

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SADD('myset', 'Hello').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
1

SCARD: Gets the number of members in a set

Redis Example

SCARD myset

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SCARD('myset').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
1

SDIFF: Subtracts multiple sets

Redis Example

SDIFF key1 key2

Output

1) "a"
2) "b"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SADD('key1', 'a', 'b', 'c', 'e').then((res) => {
  console.log(res);
  client.SADD('key2', 'a', 'b', 'd').then((res) => {
    console.log(res);
    client.SDIFF('key1', 'key2').then((res) => {
      console.log(res);
      client.quit();
    });
  });
});

Output

1
1
['a']

SDIFFSTORE: Subtracts multiple sets and stores the resulting set in a key

Redis Example

SDIFFSTORE key1 key2

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SADD('key1', 'a', 'b', 'c', 'e').then((res) => {
  console.log(res);
  client.SADD('key2', 'a', 'b', 'd').then((res) => {
    console.log(res);
    client.SDIFFSTORE('key1', 'key2').then((res) => {
      console.log(res);
      client.quit();
    });
  });
});

Output

Redis Client Connected
1
1
1

SINTER: Intersects multiple sets

Redis Example

SINTER key1 key2

Output

1
1
['a']

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SADD('key1', 'a', 'b', 'c', 'e').then((res) => {
  console.log(res);
  client.SADD('key2', 'a', 'b', 'd').then((res) => {
    console.log(res);
    client.SINTER('key1', 'key2').then((res) => {
      console.log(res);
      client.quit();
    });
  });
});

Output

Redis Client Connected
1
1
['a']

SINTERSTORE: Intersects multiple sets and stores the resulting set in a key

Redis Example

SINTERSTORE key key1 key2

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SADD('key1', 'a', 'b', 'c', 'e').then((res) => {
  console.log(res);
  client.SADD('key2', 'a', 'b', 'd').then((res) => {
    console.log(res);
    client.SINTERSTORE('key1', 'key2').then((res) => {
      console.log(res);
      client.quit();
    });
  });
});

Output

Redis Client Connected
1
1
1

SISMEMBER: Determines if a given value is a member of a set

Redis Example

SISMEMBER myset "one"

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SISMEMBER('myset', 'one').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
false

SMEMBERS: Gets all the members in a set

Redis Example

SMEMBERS myset

Output

1) "Hello"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SMEMBERS('myset').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
['Hello']

SMOVE: Moves a member from one set to another

Redis Example

 SMOVE myset myotherset "two"

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SADD('key6', 'a', 'b', 'c', 'e').then((res) => {
  console.log(res);
  client.SADD('key5', 'a', 'b', 'd', 'x').then((res) => {
    console.log(res);
    client.SMOVE('key5', 'key6', 'e').then((res) => {
      console.log(res);
      client.quit();
    });
  });
});

Output

1
1
true

SPOP: Removes and returns a random member from a set

Redis Example

SPOP myset

Output

three

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SPOP('myset').then((reply) => {
  console.log(reply);
  client.quit();
});

Output

Redis Client Connected
Hello

SRANDMEMBER: Gets one or multiple random members from a set

Redis Example

SRANDMEMBER myset -5

Output

1) "s"
2) "w"
3) "s"
4) "a"
5) "a"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SRANDMEMBER('myset', -5).then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
a

SREM: Removes one or more members from a set

Redis Example

SREM myset "a"

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SREM('myset', 'a').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
1

SUNION: Adds multiple sets

Redis Example

SUNION key1 key2

Output

1) "a"

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SUNION('key1', 'key2').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
['a']

SUNIONSTORE: Adds multiple sets and stores the resulting set in a key

Redis Example

SUNIONSTORE key key1 key2

Output

JavaScript Example

const redis = require('redis');

const client = redis.createClient();

client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('Redis Client Connected'));

client.connect();

client.SUNIONSTORE('key', 'key1', 'key2').then((res) => {
  console.log(res);
  client.quit();
});

Output

Redis Client Connected
1

DEV Community

Basic Operations with node_redis

node_redis

Installing node_redis in Javascript

Javascript Datatype Mapping with Redis Type

Redis Command Using node_redis

Hash Commands

List commands

Set Commands

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