Redis hashes
Introduction to Redis hashes
Redis hashes are record types structured as collections of field-value pairs. You can use hashes to represent basic objects and to store groupings of counters, among other things.
> HSET bike:1 model Deimos brand Ergonom type 'Enduro bikes' price 4972
(integer) 4
> HGET bike:1 model
"Deimos"
> HGET bike:1 price
"4972"
> HGETALL bike:1
1) "model"
2) "Deimos"
3) "brand"
4) "Ergonom"
5) "type"
6) "Enduro bikes"
7) "price"
8) "4972"Are you tired of using redis-cli? Try Redis Insight - the developer GUI for Redis.
import redis
r = redis.Redis(decode_responses=True)
res1 = r.hset(
"bike:1",
mapping={
"model": "Deimos",
"brand": "Ergonom",
"type": "Enduro bikes",
"price": 4972,
},
)
print(res1)
# >>> 4
res2 = r.hget("bike:1", "model")
print(res2)
# >>> 'Deimos'
res3 = r.hget("bike:1", "price")
print(res3)
# >>> '4972'
res4 = r.hgetall("bike:1")
print(res4)
# >>> {'model': 'Deimos', 'brand': 'Ergonom', 'type': 'Enduro bikes', 'price': '4972'}
res5 = r.hmget("bike:1", ["model", "price"])
print(res5)
# >>> ['Deimos', '4972']
res6 = r.hincrby("bike:1", "price", 100)
print(res6)
# >>> 5072
res7 = r.hincrby("bike:1", "price", -100)
print(res7)
# >>> 4972
res11 = r.hincrby("bike:1:stats", "rides", 1)
print(res11)
# >>> 1
res12 = r.hincrby("bike:1:stats", "rides", 1)
print(res12)
# >>> 2
res13 = r.hincrby("bike:1:stats", "rides", 1)
print(res13)
# >>> 3
res14 = r.hincrby("bike:1:stats", "crashes", 1)
print(res14)
# >>> 1
res15 = r.hincrby("bike:1:stats", "owners", 1)
print(res15)
# >>> 1
res16 = r.hget("bike:1:stats", "rides")
print(res16)
# >>> 3
res17 = r.hmget("bike:1:stats", ["crashes", "owners"])
print(res17)
# >>> ['1', '1']
package io.redis.examples;
import redis.clients.jedis.UnifiedJedis;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class HashExample {
public void run() {
try (UnifiedJedis jedis = new UnifiedJedis("redis://localhost:6379")) {
Map<String, String> bike1 = new HashMap<>();
bike1.put("model", "Deimos");
bike1.put("brand", "Ergonom");
bike1.put("type", "Enduro bikes");
bike1.put("price", "4972");
Long res1 = jedis.hset("bike:1", bike1);
System.out.println(res1); // 4
String res2 = jedis.hget("bike:1", "model");
System.out.println(res2); // Deimos
String res3 = jedis.hget("bike:1", "price");
System.out.println(res3); // 4972
Map<String, String> res4 = jedis.hgetAll("bike:1");
System.out.println(res4); // {type=Enduro bikes, brand=Ergonom, price=4972, model=Deimos}
List<String> res5 = jedis.hmget("bike:1", "model", "price");
System.out.println(res5); // [Deimos, 4972]
Long res6 = jedis.hincrBy("bike:1", "price", 100);
System.out.println(res6); // 5072
Long res7 = jedis.hincrBy("bike:1", "price", -100);
System.out.println(res7); // 4972
Long res8 = jedis.hincrBy("bike:1:stats", "rides", 1);
System.out.println(res8); // 1
Long res9 = jedis.hincrBy("bike:1:stats", "rides", 1);
System.out.println(res9); // 2
Long res10 = jedis.hincrBy("bike:1:stats", "rides", 1);
System.out.println(res10); // 3
Long res11 = jedis.hincrBy("bike:1:stats", "crashes", 1);
System.out.println(res11); // 1
Long res12 = jedis.hincrBy("bike:1:stats", "owners", 1);
System.out.println(res12); // 1
String res13 = jedis.hget("bike:1:stats", "rides");
System.out.println(res13); // 3
List<String> res14 = jedis.hmget("bike:1:stats", "crashes", "owners");
System.out.println(res14); // [1, 1]
}
}
}
using NRedisStack.Tests;
using StackExchange.Redis;
public class HashExample
{
[SkipIfRedis(Is.OSSCluster)]
public void run()
{
var muxer = ConnectionMultiplexer.Connect("localhost:6379");
var db = muxer.GetDatabase();
db.KeyDelete("bike:1");
db.HashSet("bike:1", new HashEntry[]
{
new HashEntry("model", "Deimos"),
new HashEntry("brand", "Ergonom"),
new HashEntry("type", "Enduro bikes"),
new HashEntry("price", 4972)
});
Console.WriteLine("Hash Created");
// Hash Created
var model = db.HashGet("bike:1", "model");
Console.WriteLine($"Model: {model}");
// Model: Deimos
var price = db.HashGet("bike:1", "price");
Console.WriteLine($"Price: {price}");
// Price: 4972
var bike = db.HashGetAll("bike:1");
Console.WriteLine("bike:1");
Console.WriteLine(string.Join("\n", bike.Select(b => $"{b.Name}: {b.Value}")));
// Bike:1:
// model: Deimos
// brand: Ergonom
// type: Enduro bikes
// price: 4972
var values = db.HashGet("bike:1", new RedisValue[] { "model", "price" });
Console.WriteLine(string.Join(" ", values));
// Deimos 4972
var newPrice = db.HashIncrement("bike:1", "price", 100);
Console.WriteLine($"New price: {newPrice}");
// New price: 5072
newPrice = db.HashIncrement("bike:1", "price", -100);
Console.WriteLine($"New price: {newPrice}");
// New price: 4972
var rides = db.HashIncrement("bike:1", "rides");
Console.WriteLine($"Rides: {rides}");
// Rides: 1
rides = db.HashIncrement("bike:1", "rides");
Console.WriteLine($"Rides: {rides}");
// Rides: 2
rides = db.HashIncrement("bike:1", "rides");
Console.WriteLine($"Rides: {rides}");
// Rides: 3
var crashes = db.HashIncrement("bike:1", "crashes");
Console.WriteLine($"Crashes: {crashes}");
// Crashes: 1
var owners = db.HashIncrement("bike:1", "owners");
Console.WriteLine($"Owners: {owners}");
// Owners: 1
var stats = db.HashGet("bike:1", new RedisValue[] { "crashes", "owners" });
Console.WriteLine($"Bike stats: crashes={stats[0]}, owners={stats[1]}");
// Bike stats: crashes=1, owners=1
}
}
While hashes are handy to represent objects, actually the number of fields you can put inside a hash has no practical limits (other than available memory), so you can use hashes in many different ways inside your application.
The command HSET sets multiple fields of the hash, while HGET retrieves
a single field. HMGET is similar to HGET but returns an array of values:
> HMGET bike:1 model price no-such-field
1) "Deimos"
2) "4972"
3) (nil)Are you tired of using redis-cli? Try Redis Insight - the developer GUI for Redis.
import redis
r = redis.Redis(decode_responses=True)
res1 = r.hset(
"bike:1",
mapping={
"model": "Deimos",
"brand": "Ergonom",
"type": "Enduro bikes",
"price": 4972,
},
)
print(res1)
# >>> 4
res2 = r.hget("bike:1", "model")
print(res2)
# >>> 'Deimos'
res3 = r.hget("bike:1", "price")
print(res3)
# >>> '4972'
res4 = r.hgetall("bike:1")
print(res4)
# >>> {'model': 'Deimos', 'brand': 'Ergonom', 'type': 'Enduro bikes', 'price': '4972'}
res5 = r.hmget("bike:1", ["model", "price"])
print(res5)
# >>> ['Deimos', '4972']
res6 = r.hincrby("bike:1", "price", 100)
print(res6)
# >>> 5072
res7 = r.hincrby("bike:1", "price", -100)
print(res7)
# >>> 4972
res11 = r.hincrby("bike:1:stats", "rides", 1)
print(res11)
# >>> 1
res12 = r.hincrby("bike:1:stats", "rides", 1)
print(res12)
# >>> 2
res13 = r.hincrby("bike:1:stats", "rides", 1)
print(res13)
# >>> 3
res14 = r.hincrby("bike:1:stats", "crashes", 1)
print(res14)
# >>> 1
res15 = r.hincrby("bike:1:stats", "owners", 1)
print(res15)
# >>> 1
res16 = r.hget("bike:1:stats", "rides")
print(res16)
# >>> 3
res17 = r.hmget("bike:1:stats", ["crashes", "owners"])
print(res17)
# >>> ['1', '1']
package io.redis.examples;
import redis.clients.jedis.UnifiedJedis;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class HashExample {
public void run() {
try (UnifiedJedis jedis = new UnifiedJedis("redis://localhost:6379")) {
Map<String, String> bike1 = new HashMap<>();
bike1.put("model", "Deimos");
bike1.put("brand", "Ergonom");
bike1.put("type", "Enduro bikes");
bike1.put("price", "4972");
Long res1 = jedis.hset("bike:1", bike1);
System.out.println(res1); // 4
String res2 = jedis.hget("bike:1", "model");
System.out.println(res2); // Deimos
String res3 = jedis.hget("bike:1", "price");
System.out.println(res3); // 4972
Map<String, String> res4 = jedis.hgetAll("bike:1");
System.out.println(res4); // {type=Enduro bikes, brand=Ergonom, price=4972, model=Deimos}
List<String> res5 = jedis.hmget("bike:1", "model", "price");
System.out.println(res5); // [Deimos, 4972]
Long res6 = jedis.hincrBy("bike:1", "price", 100);
System.out.println(res6); // 5072
Long res7 = jedis.hincrBy("bike:1", "price", -100);
System.out.println(res7); // 4972
Long res8 = jedis.hincrBy("bike:1:stats", "rides", 1);
System.out.println(res8); // 1
Long res9 = jedis.hincrBy("bike:1:stats", "rides", 1);
System.out.println(res9); // 2
Long res10 = jedis.hincrBy("bike:1:stats", "rides", 1);
System.out.println(res10); // 3
Long res11 = jedis.hincrBy("bike:1:stats", "crashes", 1);
System.out.println(res11); // 1
Long res12 = jedis.hincrBy("bike:1:stats", "owners", 1);
System.out.println(res12); // 1
String res13 = jedis.hget("bike:1:stats", "rides");
System.out.println(res13); // 3
List<String> res14 = jedis.hmget("bike:1:stats", "crashes", "owners");
System.out.println(res14); // [1, 1]
}
}
}
using NRedisStack.Tests;
using StackExchange.Redis;
public class HashExample
{
[SkipIfRedis(Is.OSSCluster)]
public void run()
{
var muxer = ConnectionMultiplexer.Connect("localhost:6379");
var db = muxer.GetDatabase();
db.KeyDelete("bike:1");
db.HashSet("bike:1", new HashEntry[]
{
new HashEntry("model", "Deimos"),
new HashEntry("brand", "Ergonom"),
new HashEntry("type", "Enduro bikes"),
new HashEntry("price", 4972)
});
Console.WriteLine("Hash Created");
// Hash Created
var model = db.HashGet("bike:1", "model");
Console.WriteLine($"Model: {model}");
// Model: Deimos
var price = db.HashGet("bike:1", "price");
Console.WriteLine($"Price: {price}");
// Price: 4972
var bike = db.HashGetAll("bike:1");
Console.WriteLine("bike:1");
Console.WriteLine(string.Join("\n", bike.Select(b => $"{b.Name}: {b.Value}")));
// Bike:1:
// model: Deimos
// brand: Ergonom
// type: Enduro bikes
// price: 4972
var values = db.HashGet("bike:1", new RedisValue[] { "model", "price" });
Console.WriteLine(string.Join(" ", values));
// Deimos 4972
var newPrice = db.HashIncrement("bike:1", "price", 100);
Console.WriteLine($"New price: {newPrice}");
// New price: 5072
newPrice = db.HashIncrement("bike:1", "price", -100);
Console.WriteLine($"New price: {newPrice}");
// New price: 4972
var rides = db.HashIncrement("bike:1", "rides");
Console.WriteLine($"Rides: {rides}");
// Rides: 1
rides = db.HashIncrement("bike:1", "rides");
Console.WriteLine($"Rides: {rides}");
// Rides: 2
rides = db.HashIncrement("bike:1", "rides");
Console.WriteLine($"Rides: {rides}");
// Rides: 3
var crashes = db.HashIncrement("bike:1", "crashes");
Console.WriteLine($"Crashes: {crashes}");
// Crashes: 1
var owners = db.HashIncrement("bike:1", "owners");
Console.WriteLine($"Owners: {owners}");
// Owners: 1
var stats = db.HashGet("bike:1", new RedisValue[] { "crashes", "owners" });
Console.WriteLine($"Bike stats: crashes={stats[0]}, owners={stats[1]}");
// Bike stats: crashes=1, owners=1
}
}
There are commands that are able to perform operations on individual fields
as well, like HINCRBY:
> HINCRBY bike:1 price 100
(integer) 5072
> HINCRBY bike:1 price -100
(integer) 4972Are you tired of using redis-cli? Try Redis Insight - the developer GUI for Redis.
import redis
r = redis.Redis(decode_responses=True)
res1 = r.hset(
"bike:1",
mapping={
"model": "Deimos",
"brand": "Ergonom",
"type": "Enduro bikes",
"price": 4972,
},
)
print(res1)
# >>> 4
res2 = r.hget("bike:1", "model")
print(res2)
# >>> 'Deimos'
res3 = r.hget("bike:1", "price")
print(res3)
# >>> '4972'
res4 = r.hgetall("bike:1")
print(res4)
# >>> {'model': 'Deimos', 'brand': 'Ergonom', 'type': 'Enduro bikes', 'price': '4972'}
res5 = r.hmget("bike:1", ["model", "price"])
print(res5)
# >>> ['Deimos', '4972']
res6 = r.hincrby("bike:1", "price", 100)
print(res6)
# >>> 5072
res7 = r.hincrby("bike:1", "price", -100)
print(res7)
# >>> 4972
res11 = r.hincrby("bike:1:stats", "rides", 1)
print(res11)
# >>> 1
res12 = r.hincrby("bike:1:stats", "rides", 1)
print(res12)
# >>> 2
res13 = r.hincrby("bike:1:stats", "rides", 1)
print(res13)
# >>> 3
res14 = r.hincrby("bike:1:stats", "crashes", 1)
print(res14)
# >>> 1
res15 = r.hincrby("bike:1:stats", "owners", 1)
print(res15)
# >>> 1
res16 = r.hget("bike:1:stats", "rides")
print(res16)
# >>> 3
res17 = r.hmget("bike:1:stats", ["crashes", "owners"])
print(res17)
# >>> ['1', '1']
package io.redis.examples;
import redis.clients.jedis.UnifiedJedis;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
public class HashExample {
public void run() {
try (UnifiedJedis jedis = new UnifiedJedis("redis://localhost:6379")) {
Map<String, String> bike1 = new HashMap<>();
bike1.put("model", "Deimos");
bike1.put("brand", "Ergonom");
bike1.put("type", "Enduro bikes");
bike1.put("price", "4972");
Long res1 = jedis.hset("bike:1", bike1);
System.out.println(res1); // 4
String res2 = jedis.hget("bike:1", "model");
System.out.println(res2); // Deimos
String res3 = jedis.hget("bike:1", "price");
System.out.println(res3); // 4972
Map<String, String> res4 = jedis.hgetAll("bike:1");
System.out.println(res4); // {type=Enduro bikes, brand=Ergonom, price=4972, model=Deimos}
List<String> res5 = jedis.hmget("bike:1", "model", "price");
System.out.println(res5); // [Deimos, 4972]
Long res6 = jedis.hincrBy("bike:1", "price", 100);
System.out.println(res6); // 5072
Long res7 = jedis.hincrBy("bike:1", "price", -100);
System.out.println(res7); // 4972
Long res8 = jedis.hincrBy("bike:1:stats", "rides", 1);
System.out.println(res8); // 1
Long res9 = jedis.hincrBy("bike:1:stats", "rides", 1);
System.out.println(res9); // 2
Long res10 = jedis.hincrBy("bike:1:stats", "rides", 1);
System.out.println(res10); // 3
Long res11 = jedis.hincrBy("bike:1:stats", "crashes", 1);
System.out.println(res11); // 1
Long res12 = jedis.hincrBy("bike:1:stats", "owners", 1);
System.out.println(res12); // 1
String res13 = jedis.hget("bike:1:stats", "rides");
System.out.println(res13); // 3
List<String> res14 = jedis.hmget("bike:1:stats", "crashes", "owners");
System.out.println(res14); // [1, 1]
}
}
}
using NRedisStack.Tests;
using StackExchange.Redis;
public class HashExample
{
[SkipIfRedis(Is.OSSCluster)]
public void run()
{
var muxer = ConnectionMultiplexer.Connect("localhost:6379");
var db = muxer.GetDatabase();
db.KeyDelete("bike:1");
db.HashSet("bike:1", new HashEntry[]
{
new HashEntry("model", "Deimos"),
new HashEntry("brand", "Ergonom"),
new HashEntry("type", "Enduro bikes"),
new HashEntry("price", 4972)
});
Console.WriteLine("Hash Created");
// Hash Created
var model = db.HashGet("bike:1", "model");
Console.WriteLine($"Model: {model}");
// Model: Deimos
var price = db.HashGet("bike:1", "price");
Console.WriteLine($"Price: {price}");
// Price: 4972
var bike = db.HashGetAll("bike:1");
Console.WriteLine("bike:1");
Console.WriteLine(string.Join("\n", bike.Select(b => $"{b.Name}: {b.Value}")));
// Bike:1:
// model: Deimos
// brand: Ergonom
// type: Enduro bikes
// price: 4972
var values = db.HashGet("bike:1", new RedisValue[] { "model", "price" });
Console.WriteLine(string.Join(" ", values));
// Deimos 4972
var newPrice = db.HashIncrement("bike:1", "price", 100);
Console.WriteLine($"New price: {newPrice}");
// New price: 5072
newPrice = db.HashIncrement("bike:1", "price", -100);
Console.WriteLine($"New price: {newPrice}");
// New price: 4972
var rides = db.HashIncrement("bike:1", "rides");
Console.WriteLine($"Rides: {rides}");
// Rides: 1
rides = db.HashIncrement("bike:1", "rides");
Console.WriteLine($"Rides: {rides}");
// Rides: 2
rides = db.HashIncrement("bike:1", "rides");
Console.WriteLine($"Rides: {rides}");
// Rides: 3
var crashes = db.HashIncrement("bike:1", "crashes");
Console.WriteLine($"Crashes: {crashes}");
// Crashes: 1
var owners = db.HashIncrement("bike:1", "owners");
Console.WriteLine($"Owners: {owners}");
// Owners: 1
var stats = db.HashGet("bike:1", new RedisValue[] { "crashes", "owners" });
Console.WriteLine($"Bike stats: crashes={stats[0]}, owners={stats[1]}");
// Bike stats: crashes=1, owners=1
}
}
You can find the full list of hash commands in the documentation.
It is worth noting that small hashes (i.e., a few elements with small values) are encoded in special way in memory that make them very memory efficient.
Basic commands
HSETsets the value of one or more fields on a hash.HGETreturns the value at a given field.HMGETreturns the values at one or more given fields.HINCRBYincrements the value at a given field by the integer provided.
See the complete list of hash commands.
Examples
- Store counters for the number of times bike:1 has been ridden, has crashed, or has changed owners:
> HINCRBY bike:1:stats rides 1 (integer) 1 > HINCRBY bike:1:stats rides 1 (integer) 2 > HINCRBY bike:1:stats rides 1 (integer) 3 > HINCRBY bike:1:stats crashes 1 (integer) 1 > HINCRBY bike:1:stats owners 1 (integer) 1 > HGET bike:1:stats rides "3" > HMGET bike:1:stats owners crashes 1) "1" 2) "1"Are you tired of using redis-cli? Try Redis Insight - the developer GUI for Redis.import redis r = redis.Redis(decode_responses=True) res1 = r.hset( "bike:1", mapping={ "model": "Deimos", "brand": "Ergonom", "type": "Enduro bikes", "price": 4972, }, ) print(res1) # >>> 4 res2 = r.hget("bike:1", "model") print(res2) # >>> 'Deimos' res3 = r.hget("bike:1", "price") print(res3) # >>> '4972' res4 = r.hgetall("bike:1") print(res4) # >>> {'model': 'Deimos', 'brand': 'Ergonom', 'type': 'Enduro bikes', 'price': '4972'} res5 = r.hmget("bike:1", ["model", "price"]) print(res5) # >>> ['Deimos', '4972'] res6 = r.hincrby("bike:1", "price", 100) print(res6) # >>> 5072 res7 = r.hincrby("bike:1", "price", -100) print(res7) # >>> 4972 res11 = r.hincrby("bike:1:stats", "rides", 1) print(res11) # >>> 1 res12 = r.hincrby("bike:1:stats", "rides", 1) print(res12) # >>> 2 res13 = r.hincrby("bike:1:stats", "rides", 1) print(res13) # >>> 3 res14 = r.hincrby("bike:1:stats", "crashes", 1) print(res14) # >>> 1 res15 = r.hincrby("bike:1:stats", "owners", 1) print(res15) # >>> 1 res16 = r.hget("bike:1:stats", "rides") print(res16) # >>> 3 res17 = r.hmget("bike:1:stats", ["crashes", "owners"]) print(res17) # >>> ['1', '1']package io.redis.examples; import redis.clients.jedis.UnifiedJedis; import java.util.HashMap; import java.util.List; import java.util.Map; public class HashExample { public void run() { try (UnifiedJedis jedis = new UnifiedJedis("redis://localhost:6379")) { Map<String, String> bike1 = new HashMap<>(); bike1.put("model", "Deimos"); bike1.put("brand", "Ergonom"); bike1.put("type", "Enduro bikes"); bike1.put("price", "4972"); Long res1 = jedis.hset("bike:1", bike1); System.out.println(res1); // 4 String res2 = jedis.hget("bike:1", "model"); System.out.println(res2); // Deimos String res3 = jedis.hget("bike:1", "price"); System.out.println(res3); // 4972 Map<String, String> res4 = jedis.hgetAll("bike:1"); System.out.println(res4); // {type=Enduro bikes, brand=Ergonom, price=4972, model=Deimos} List<String> res5 = jedis.hmget("bike:1", "model", "price"); System.out.println(res5); // [Deimos, 4972] Long res6 = jedis.hincrBy("bike:1", "price", 100); System.out.println(res6); // 5072 Long res7 = jedis.hincrBy("bike:1", "price", -100); System.out.println(res7); // 4972 Long res8 = jedis.hincrBy("bike:1:stats", "rides", 1); System.out.println(res8); // 1 Long res9 = jedis.hincrBy("bike:1:stats", "rides", 1); System.out.println(res9); // 2 Long res10 = jedis.hincrBy("bike:1:stats", "rides", 1); System.out.println(res10); // 3 Long res11 = jedis.hincrBy("bike:1:stats", "crashes", 1); System.out.println(res11); // 1 Long res12 = jedis.hincrBy("bike:1:stats", "owners", 1); System.out.println(res12); // 1 String res13 = jedis.hget("bike:1:stats", "rides"); System.out.println(res13); // 3 List<String> res14 = jedis.hmget("bike:1:stats", "crashes", "owners"); System.out.println(res14); // [1, 1] } } }using NRedisStack.Tests; using StackExchange.Redis; public class HashExample { [SkipIfRedis(Is.OSSCluster)] public void run() { var muxer = ConnectionMultiplexer.Connect("localhost:6379"); var db = muxer.GetDatabase(); db.KeyDelete("bike:1"); db.HashSet("bike:1", new HashEntry[] { new HashEntry("model", "Deimos"), new HashEntry("brand", "Ergonom"), new HashEntry("type", "Enduro bikes"), new HashEntry("price", 4972) }); Console.WriteLine("Hash Created"); // Hash Created var model = db.HashGet("bike:1", "model"); Console.WriteLine($"Model: {model}"); // Model: Deimos var price = db.HashGet("bike:1", "price"); Console.WriteLine($"Price: {price}"); // Price: 4972 var bike = db.HashGetAll("bike:1"); Console.WriteLine("bike:1"); Console.WriteLine(string.Join("\n", bike.Select(b => $"{b.Name}: {b.Value}"))); // Bike:1: // model: Deimos // brand: Ergonom // type: Enduro bikes // price: 4972 var values = db.HashGet("bike:1", new RedisValue[] { "model", "price" }); Console.WriteLine(string.Join(" ", values)); // Deimos 4972 var newPrice = db.HashIncrement("bike:1", "price", 100); Console.WriteLine($"New price: {newPrice}"); // New price: 5072 newPrice = db.HashIncrement("bike:1", "price", -100); Console.WriteLine($"New price: {newPrice}"); // New price: 4972 var rides = db.HashIncrement("bike:1", "rides"); Console.WriteLine($"Rides: {rides}"); // Rides: 1 rides = db.HashIncrement("bike:1", "rides"); Console.WriteLine($"Rides: {rides}"); // Rides: 2 rides = db.HashIncrement("bike:1", "rides"); Console.WriteLine($"Rides: {rides}"); // Rides: 3 var crashes = db.HashIncrement("bike:1", "crashes"); Console.WriteLine($"Crashes: {crashes}"); // Crashes: 1 var owners = db.HashIncrement("bike:1", "owners"); Console.WriteLine($"Owners: {owners}"); // Owners: 1 var stats = db.HashGet("bike:1", new RedisValue[] { "crashes", "owners" }); Console.WriteLine($"Bike stats: crashes={stats[0]}, owners={stats[1]}"); // Bike stats: crashes=1, owners=1 } }
Performance
Most Redis hash commands are O(1).
A few commands - such as HKEYS, HVALS, and HGETALL - are O(n), where n is the number of field-value pairs.
Limits
Every hash can store up to 4,294,967,295 (2^32 - 1) field-value pairs. In practice, your hashes are limited only by the overall memory on the VMs hosting your Redis deployment.
Learn more
- Redis Hashes Explained is a short, comprehensive video explainer covering Redis hashes.
- Redis University's RU101 covers Redis hashes in detail.