Redis 简介和基本数据类型
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简介
Redis 是一个开源（BSD许可）的，内存中的数据结构存储系统，它可以用作数据库、缓存和消息中间件。它支持多种类型的数据结构：字符串（strings）， 散列（hashes）， 列表（lists）， 集合（sets）， 有序集合（sorted sets） 与范围查询，位图（ bitmaps） hyperloglogs 和 地理空间（geospatial） 索引半径查询。Redis 内置了 复制（replication），LUA脚本（Lua scripting）， LRU驱动事件（LRU eviction），事务（transactions） 和不同级别的 磁盘持久化（persistence）， 并通过 Redis哨兵（Sentinel）和自动 分区（Cluster）提供高可用性（high availability）。
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基本数据类型
基本数据类型 ：字符串（strings）， 散列（hashes）， 列表（lists）， 集合（sets）， 有序集合（sorted sets）
2.1 字符串（strings）
二进制安全的字符串
通过 客户端命令 help @string 查看 string 的命令help @string APPEND key value summary: Append a value to a key since: 2.0.0 BITCOUNT key [start end] summary: Count set bits in a string since: 2.6.0 BITFIELD key [GET type offset] [SET type offset value] [INCRBY type offset increment] [OVERFLOW WRAP|SAT|FAIL] summary: Perform arbitrary bitfield integer operations on strings since: 3.2.0 BITOP operation destkey key [key ...] summary: Perform bitwise operations between strings since: 2.6.0 BITPOS key bit [start] [end] summary: Find first bit set or clear in a string since: 2.8.7 DECR key summary: Decrement the integer value of a key by one since: 1.0.0 DECRBY key decrement summary: Decrement the integer value of a key by the given number since: 1.0.0 GET key summary: Get the value of a key since: 1.0.0 GETBIT key offset summary: Returns the bit value at offset in the string value stored at key since: 2.2.0 GETRANGE key start end summary: Get a substring of the string stored at a key since: 2.4.0 GETSET key value summary: Set the string value of a key and return its old value since: 1.0.0 INCR key summary: Increment the integer value of a key by one since: 1.0.0 INCRBY key increment summary: Increment the integer value of a key by the given amount since: 1.0.0 INCRBYFLOAT key increment summary: Increment the float value of a key by the given amount since: 2.6.0 MGET key [key ...] summary: Get the values of all the given keys since: 1.0.0 MSET key value [key value ...] summary: Set multiple keys to multiple values since: 1.0.1 MSETNX key value [key value ...] summary: Set multiple keys to multiple values, only if none of the keys exist since: 1.0.1 PSETEX key milliseconds value summary: Set the value and expiration in milliseconds of a key since: 2.6.0 SET key value [EX seconds] [PX milliseconds] [NX|XX] summary: Set the string value of a key since: 1.0.0 SETBIT key offset value summary: Sets or clears the bit at offset in the string value stored at key since: 2.2.0 SETEX key seconds value summary: Set the value and expiration of a key since: 2.0.0 SETNX key value summary: Set the value of a key, only if the key does not exist since: 1.0.0 SETRANGE key offset value summary: Overwrite part of a string at key starting at the specified offset since: 2.2.0 STRLEN key summary: Get the length of the value stored in a key since: 2.2.0
2.2 散列（hashes）
Redis hash 看起来就像一个 “hash” 的样子，value 由键值对组成
help @hash
HDEL key field [field ...]
summary: Delete one or more hash fields
since: 2.0.0
HEXISTS key field
summary: Determine if a hash field exists
since: 2.0.0
HGET key field
summary: Get the value of a hash field
since: 2.0.0
HGETALL key
summary: Get all the fields and values in a hash
since: 2.0.0
HINCRBY key field increment
summary: Increment the integer value of a hash field by the given number
since: 2.0.0
HINCRBYFLOAT key field increment
summary: Increment the float value of a hash field by the given amount
since: 2.6.0
HKEYS key
summary: Get all the fields in a hash
since: 2.0.0
HLEN key
summary: Get the number of fields in a hash
since: 2.0.0
HMGET key field [field ...]
summary: Get the values of all the given hash fields
since: 2.0.0
HMSET key field value [field value ...]
summary: Set multiple hash fields to multiple values
since: 2.0.0
HSCAN key cursor [MATCH pattern] [COUNT count]
summary: Incrementally iterate hash fields and associated values
since: 2.8.0
HSET key field value
summary: Set the string value of a hash field
since: 2.0.0
HSETNX key field value
summary: Set the value of a hash field, only if the field does not exist
since: 2.0.0
HSTRLEN key field
summary: Get the length of the value of a hash field
since: 3.2.0
HVALS key
summary: Get all the values in a hash
since: 2.0.0
例子：
hmset user:1000 username antirez birthyear 1977 verified 1
OK
hget user:1000 username
“antirez”
hget user:1000 birthyear
“1977”
hgetall user:1000
1) “username”
2) “antirez”
3) “birthyear”
4) “1977”
5) “verified”
6) “1”
2.3 列表（lists）
Lists: 按插入顺序排序的字符串元素的集合。他们基本上就是链表（linked lists）。
help @list
BLPOP key [key ...] timeout
summary: Remove and get the first element in a list, or block until one is available
since: 2.0.0
BRPOP key [key ...] timeout
summary: Remove and get the last element in a list, or block until one is available
since: 2.0.0
BRPOPLPUSH source destination timeout
summary: Pop a value from a list, push it to another list and return it; or block until one is available
since: 2.2.0
LINDEX key index
summary: Get an element from a list by its index
since: 1.0.0
LINSERT key BEFORE|AFTER pivot value
summary: Insert an element before or after another element in a list
since: 2.2.0
LLEN key
summary: Get the length of a list
since: 1.0.0
LPOP key
summary: Remove and get the first element in a list
since: 1.0.0
LPUSH key value [value ...]
summary: Prepend one or multiple values to a list
since: 1.0.0
LPUSHX key value
summary: Prepend a value to a list, only if the list exists
since: 2.2.0
LRANGE key start stop
summary: Get a range of elements from a list
since: 1.0.0
LREM key count value
summary: Remove elements from a list
since: 1.0.0
LSET key index value
summary: Set the value of an element in a list by its index
since: 1.0.0
LTRIM key start stop
summary: Trim a list to the specified range
since: 1.0.0
RPOP key
summary: Remove and get the last element in a list
since: 1.0.0
RPOPLPUSH source destination
summary: Remove the last element in a list, prepend it to another list and return it
since: 1.2.0
RPUSH key value [value ...]
summary: Append one or multiple values to a list
since: 1.0.0
RPUSHX key value
summary: Append a value to a list, only if the list exists
since: 2.2.0
2.4 集合（sets）
Redis Set 是 String 的无序排列。SADD 指令把新的元素添加到 set 中。对 set 也可做一些其他的操作，比如测试一个给定的元素是否存在，对不同 set 取交集，并集或差，等等。
help @set
SADD key member [member ...]
summary: Add one or more members to a set
since: 1.0.0
SCARD key
summary: Get the number of members in a set
since: 1.0.0
SDIFF key [key ...]
summary: Subtract multiple sets
since: 1.0.0
SDIFFSTORE destination key [key ...]
summary: Subtract multiple sets and store the resulting set in a key
since: 1.0.0
SINTER key [key ...]
summary: Intersect multiple sets
since: 1.0.0
SINTERSTORE destination key [key ...]
summary: Intersect multiple sets and store the resulting set in a key
since: 1.0.0
SISMEMBER key member
summary: Determine if a given value is a member of a set
since: 1.0.0
SMEMBERS key
summary: Get all the members in a set
since: 1.0.0
SMOVE source destination member
summary: Move a member from one set to another
since: 1.0.0
SPOP key [count]
summary: Remove and return one or multiple random members from a set
since: 1.0.0
SRANDMEMBER key [count]
summary: Get one or multiple random members from a set
since: 1.0.0
SREM key member [member ...]
summary: Remove one or more members from a set
since: 1.0.0
SSCAN key cursor [MATCH pattern] [COUNT count]
summary: Incrementally iterate Set elements
since: 2.8.0
SUNION key [key ...]
summary: Add multiple sets
since: 1.0.0
SUNIONSTORE destination key [key ...]
summary: Add multiple sets and store the resulting set in a key
since: 1.0.0
2.5 有序集合（sorted sets）
查看命令集 127.0.0.1:6379> help @sorted_set
ZADD key [NX|XX] [CH] [INCR] score member [score member ...]
summary: Add one or more members to a sorted set, or update its score if it already exists
since: 1.2.0
ZCARD key
summary: Get the number of members in a sorted set
since: 1.2.0
ZCOUNT key min max
summary: Count the members in a sorted set with scores within the given values
since: 2.0.0
ZINCRBY key increment member
summary: Increment the score of a member in a sorted set
since: 1.2.0
ZINTERSTORE destination numkeys key [key ...] [WEIGHTS weight] [AGGREGATE SUM|MIN|MAX]
summary: Intersect multiple sorted sets and store the resulting sorted set in a new key
since: 2.0.0
ZLEXCOUNT key min max
summary: Count the number of members in a sorted set between a given lexicographical range
since: 2.8.9
ZRANGE key start stop [WITHSCORES]
summary: Return a range of members in a sorted set, by index
since: 1.2.0
ZRANGEBYLEX key min max [LIMIT offset count]
summary: Return a range of members in a sorted set, by lexicographical range
since: 2.8.9
ZRANGEBYSCORE key min max [WITHSCORES] [LIMIT offset count]
summary: Return a range of members in a sorted set, by score
since: 1.0.5
ZRANK key member
summary: Determine the index of a member in a sorted set
since: 2.0.0
ZREM key member [member ...]
summary: Remove one or more members from a sorted set
since: 1.2.0
ZREMRANGEBYLEX key min max
summary: Remove all members in a sorted set between the given lexicographical range
since: 2.8.9
ZREMRANGEBYRANK key start stop
summary: Remove all members in a sorted set within the given indexes
since: 2.0.0
ZREMRANGEBYSCORE key min max
summary: Remove all members in a sorted set within the given scores
since: 1.2.0
ZREVRANGE key start stop [WITHSCORES]
summary: Return a range of members in a sorted set, by index, with scores ordered from high to low
since: 1.2.0
ZREVRANGEBYLEX key max min [LIMIT offset count]
summary: Return a range of members in a sorted set, by lexicographical range, ordered from higher to lower strings.
since: 2.8.9
ZREVRANGEBYSCORE key max min [WITHSCORES] [LIMIT offset count]
summary: Return a range of members in a sorted set, by score, with scores ordered from high to low
since: 2.2.0
ZREVRANK key member
summary: Determine the index of a member in a sorted set, with scores ordered from high to low
since: 2.0.0
ZSCAN key cursor [MATCH pattern] [COUNT count]
summary: Incrementally iterate sorted sets elements and associated scores
since: 2.8.0
ZSCORE key member
summary: Get the score associated with the given member in a sorted set
since: 1.2.0
ZUNIONSTORE destination numkeys key [key ...] [WEIGHTS weight] [AGGREGATE SUM|MIN|MAX]
summary: Add multiple sorted sets and store the resulting sorted set in a new key
since: 2.0.0
例子：
zadd hackers 1940 “Alan Kay”
(integer) 1
zadd hackers 1957 “Sophie Wilson”
(integer 1)
zadd hackers 1953 “Richard Stallman”
(integer) 1
zadd hackers 1949 “Anita Borg”
(integer) 1
zadd hackers 1965 “Yukihiro Matsumoto”
(integer) 1
zadd hackers 1914 “Hedy Lamarr”
(integer) 1
zadd hackers 1916 “Claude Shannon”
(integer) 1
zadd hackers 1969 “Linus Torvalds”
(integer) 1
zadd hackers 1912 “Alan Turing”
(integer) 1
查看集合中数据
zrange hackers 0 -1
1) "Alan Turing"
2) "Hedy Lamarr"
3) "Claude Shannon"
4) "Alan Kay"
5) "Anita Borg"
6) "Richard Stallman"
7) "Sophie Wilson"
8) "Yukihiro Matsumoto"
9) "Linus Torvalds"
> zrevrange hackers 0 -1
1) "Linus Torvalds"
2) "Yukihiro Matsumoto"
3) "Sophie Wilson"
4) "Richard Stallman"
5) "Anita Borg"
6) "Alan Kay"
7) "Claude Shannon"
8) "Hedy Lamarr"
9) "Alan Turing"