Redis数据结构
Redis是一个key-value的数据库,key一般是String类型,不过value的类型多种多样:
字符串(String)
:最常见的值类型,可以存储任意长度的字符串。哈希(Hash)
:一个键值对的集合,类似于关联数组或字典。每个哈希可以存储多个字段和对应的值。列表(List)
:一个有序的字符串元素集合,可以在列表的两端进行插入、删除和访问操作。集合(Set)
:一个无序的字符串元素集合,不允许重复元素。可以进行集合操作,如交集、并集、差集等。有序集合(Sorted Set)
:类似于集合,但每个元素都关联着一个分数,用于排序和按范围查询。地理位置(Geospatial)
:用于存储地理位置信息的数据类型,可以进行附近位置查询和距离计算。
除了上述数据类型,Redis还提供了一些特殊的数据结构和功能,如位图(Bitmap)、HyperLogLog、Pub/Sub(发布订阅)等。
通过使用不同的数据类型,Redis可以适应各种场景和需求,提供高效的数据存储和访问。您可以根据具体的应用需求选择适合的数据类型来存储和操作数据。
在redis-cli中要获取关于数据类型的帮助信息,可以在redis-cli中输入以下命令来获取相关帮助:(help @数据类型
)
127.0.0.1:6380> help @string
APPEND key value
summary: Appends a string to the value of a key. Creates the key if it doesn't exist.
since: 2.0.0
DECR key
summary: Decrements the integer value of a key by one. Uses 0 as initial value if the key doesn't exist.
since: 1.0.0
DECRBY key decrement
summary: Decrements a number from the integer value of a key. Uses 0 as initial value if the key doesn't exist.
since: 1.0.0
GET key
summary: Returns the string value of a key.
since: 1.0.0
GETDEL key
summary: Returns the string value of a key after deleting the key.
since: 6.2.0
GETEX key [EX seconds|PX milliseconds|EXAT unix-time-seconds|PXAT unix-time-milliseconds|PERSIST]
summary: Returns the string value of a key after setting its expiration time.
since: 6.2.0
GETRANGE key start end
summary: Returns a substring of the string stored at a key.
since: 2.4.0
GETSET key value
summary: Returns the previous string value of a key after setting it to a new value.
since: 1.0.0
INCR key
summary: Increments the integer value of a key by one. Uses 0 as initial value if the key doesn't exist.
since: 1.0.0
INCRBY key increment
summary: Increments the integer value of a key by a number. Uses 0 as initial value if the key doesn't exist.
since: 1.0.0
INCRBYFLOAT key increment
summary: Increment the floating point value of a key by a number. Uses 0 as initial value if the key doesn't exist.
since: 2.6.0
LCS key1 key2 [LEN] [IDX] [MINMATCHLEN min-match-len] [WITHMATCHLEN]
summary: Finds the longest common substring.
since: 7.0.0
MGET key [key ...]
summary: Atomically returns the string values of one or more keys.
since: 1.0.0
MSET key value [key value ...]
summary: Atomically creates or modifies the string values of one or more keys.
since: 1.0.1
MSETNX key value [key value ...]
summary: Atomically modifies the string values of one or more keys only when all keys don't exist.
since: 1.0.1
PSETEX key milliseconds value
summary: Sets both string value and expiration time in milliseconds of a key. The key is created if it doesn't exist.
since: 2.6.0
SET key value [NX|XX] [GET] [EX seconds|PX milliseconds|EXAT unix-time-seconds|PXAT unix-time-milliseconds|KEEPTTL]
summary: Sets the string value of a key, ignoring its type. The key is created if it doesn't exist.
since: 1.0.0
SETEX key seconds value
summary: Sets the string value and expiration time of a key. Creates the key if it doesn't exist.
since: 2.0.0
SETNX key value
summary: Set the string value of a key only when the key doesn't exist.
since: 1.0.0
SETRANGE key offset value
summary: Overwrites a part of a string value with another by an offset. Creates the key if it doesn't exist.
since: 2.2.0
STRLEN key
summary: Returns the length of a string value.
since: 2.2.0
SUBSTR key start end
summary: Returns a substring from a string value.
since: 1.0.0
127.0.0.1:6380>
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