Redis is a key-value database. The type of key can only be String, but the data type of value is richer, mainly including five types:
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String
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Hash
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List
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Set
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Sorted Set
1. String
grammar
SET KEY_NAME VALUE
The string type is binary safe. This means that the redis string can contain any data. Such as jpg images or serialized objects. The string type is the most basic data type of Redis, and a key can store up to 512MB.
2. Hash
grammar
HSET KEY_NAME FIELD VALUE
Redis hash is a collection of key-value (key=>value) pairs. Redis hash is a mapping table between field and value of string type, and hash is particularly suitable for storing objects.
3. List
grammar
//在 key 对应 list 的头部添加字符串元素 LPUSH KEY_NAME VALUE1.. VALUEN//在 key 对应 list 的尾部添加字符串元素 RPUSH KEY_NAME VALUE1..VALUEN//对应 list 中删除 count 个和 value 相同的元素 LREM KEY_NAME COUNT VALUE//返回 key 对应 list 的长度 LLEN KEY_NAME
Redis lists are simple lists of strings, sorted in the order of insertion. You can add an element to the head (left) or tail (right) of the list
4. Set collection
grammar
SADD KEY_NAME VALUE1...VALUEn
Redis Set is an unordered collection of string type. The collection is implemented through a hash table, so the complexity of adding, deleting, and searching is O(1).
5. Sorted Set ordered set
grammar
ZADD KEY_NAME SCORE1 VALUE1.. SCOREN VALUEN
Redis zset, like set, is also a collection of string type elements, and duplicate members are not allowed. The difference is that each element is associated with a double type score.
Redis uses scores to sort the members of the set from small to large.
The members of zset are unique, but the score (score) can be repeated.
6. Redis common command reference
For more command syntax, please refer to the official website manual:
https://www.redis.net.cn/order/
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