Redis 简明教程

Redis - Hashes

Redis 哈希是字符串字段和字符串值之间的映射。因此，它们是表示对象的理想数据类型。

Redis Hashes are maps between the string fields and the string values. Hence, they are the perfect data type to represent objects.

在 Redis 中，每个哈希最多可存储超过 40 亿个字段-值对。

In Redis, every hash can store up to more than 4 billion field-value pairs.

Example

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

在上面的示例中，我们在名为“tutorialspoint”的哈希中设置了 Redis 教程详细信息（名称、说明、喜欢数、访问数）。

In the above example, we have set Redis tutorials detail (name, description, likes, visitors) in hash named ‘tutorialspoint’.

Redis Hash Commands

下表列出了与哈希相关的某些基本命令。

Following table lists some basic commands related to hash.

Sr.No	Command & Description
1	HDEL key field2 [field2]Deletes one or more hash fields.
2	HEXISTS key fieldDetermines whether a hash field exists or not.
3	HGET key fieldGets the value of a hash field stored at the specified key.
4	HGETALL keyGets all the fields and values stored in a hash at the specified key
5	HINCRBY key field incrementIncrements the integer value of a hash field by the given number
6	HINCRBYFLOAT key field incrementIncrements the float value of a hash field by the given amount
7	HKEYS keyGets all the fields in a hash
8	HLEN keyGets the number of fields in a hash
9	HMGET key field1 [field2]Gets the values of all the given hash fields
10	HMSET key field1 value1 [field2 value2 ]Sets multiple hash fields to multiple values
11	HSET key field valueSets the string value of a hash field
12	HSETNX key field valueSets the value of a hash field, only if the field does not exist
13	HVALS keyGets all the values in a hash
14	HSCAN key cursor [MATCH pattern] [COUNT count]Incrementally iterates hash fields and associated values