Redis Hash

Redis hash is a mapping table of string type fields and values, and hash is especially suitable for storing objects.

Each hash in Redis can store 232^32 - 1 key-value pairs (over 4 billion).

Example

127.0.0.1:6379>  HMSET examplekey name "redis tutorial" description "redis basic commands for caching" likes 20 visitors 23000
OK
127.0.0.1:6379>  HGETALL examplekey
1) "name"
2) "redis tutorial"
3) "description"
4) "redis basic commands for caching"
5) "likes"
6) "20"
7) "visitors"
8) "23000"

In the above example, we set some description information (name, description, likes, visitors) of redis into the hash tableexamplekey.

Redis hash commands

The following table lists the basic commands related to redis hash:

Serial numberCommand and description
1HDEL key field1 [field2]
Delete one or more hash table fields
2HEXISTS key field
Check whether the specified field exists in the hash table key.
3HGET key field
Get the value of the specified field stored in the hash table.
4HGETALL key
Get all fields and values of the specified key in the hash table
5HINCRBY key field increment
Add the increment increment to the integer value of the specified field in the hash table key.
6HINCRBYFLOAT key field increment
Add the increment increment to the floating-point value of the specified field in the hash table key.
7HKEYS key
Get all fields in the hash table
8HLEN key
Get the number of fields in the hash table
9HMGET key field1 [field2]
Get the values of all given fields
10HMSET key field1 value1 [field2 value2 ]
Set multiple field-value pairs into the hash table key at the same time.
11HSET key field value
Set the value of the field field in the hash table key to value.
12HSETNX key field value
Set the value of the hash table field only when the field field does not exist.
13HVALS key
Get all values in the hash table.
14HSCAN key cursor [MATCH pattern] [COUNT count]
Iterate over key-value pairs in the hash table.

For more commands, please refer to:https://redis.io/commands

Other extensions