Redis数据结构之列表
目录
Redis数据结构之列表
Redis列表是简单的字符串列表，按照插入顺序排序。你可以添加一个元素到列表的头部（左边）或者尾部（右边）一个列表最多可以包含 2^32 - 1 个元素 (4294967295, 每个列表超过40亿个元素)。
查看命令帮助
127.0.0.1:6379> 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 an element 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 element
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
LPOS key element [RANK rank] [COUNT num-matches] [MAXLEN len]
summary: Return the index of matching elements on a list
since: 6.0.6
LPUSH key element [element ...]
summary: Prepend one or multiple elements to a list
since: 1.0.0
LPUSHX key element [element ...]
summary: Prepend an element 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 element
summary: Remove elements from a list
since: 1.0.0
LSET key index element
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 element [element ...]
summary: Append one or multiple elements to a list
since: 1.0.0
RPUSHX key element [element ...]
summary: Append an element to a list, only if the list exists
since: 2.2.0
创建列表
从左边插入元素
LPUSH
127.0.0.1:6379> LPUSH mylist ddfff 21 nb
(integer) 3
127.0.0.1:6379> LRANGE mylist 0 -1
1) "nb"
2) "21"
3) "ddfff"
从右边插入数据
RPUSH
127.0.0.1:6379> RPUSH mylist qq ll nn
(integer) 6
127.0.0.1:6379> LRANGE mylist 0 -1
1) "nb"
2) "21"
3) "ddfff"
4) "qq"
5) "ll"
6) "nn"
若list存在，则从左边依次追加元素，不存在则忽略
LPUSHX
127.0.0.1:6379> LPUSHX mylist ww ee
(integer) 8
127.0.0.1:6379> LRANGE mylist 0 -1
1) "ee"
2) "ww"
3) "nb"
4) "21"
5) "ddfff"
6) "qq"
7) "ll"
8) "nn"
127.0.0.1:6379> LPUSHX youlist ww ee
(integer) 0
127.0.0.1:6379> LRANGE youlist 0 -1
(empty array)
若list存在，则从右边依次追加元素，不存在则忽略
RPUSHX
127.0.0.1:6379> RPUSHX mylist rr nn
(integer) 10
127.0.0.1:6379> LRANGE mylist 0 -1
1) "ee"
2) "ww"
3) "nb"
4) "21"
5) "ddfff"
6) "qq"
7) "ll"
8) "nn"
9) "rr"
10) "nn"
127.0.0.1:6379> RPUSHX youlist rr nn
(integer) 0
127.0.0.1:6379> LRANGE youlist 0 -1
(empty array)
从list中指定的元素前/后插入一个新元素
LINSERT
127.0.0.1:6379> LRANGE mylist 0 -1
1) "ee"
2) "ww"
3) "nb"
4) "21"
5) "ddfff"
6) "qq"
7) "ll"
#在指定元素前插入新元素
127.0.0.1:6379> LINSERT mylist before ddfff www
(integer) 8
127.0.0.1:6379> LRANGE mylist 0 -1
1) "ee"
2) "ww"
3) "nb"
4) "21"
5) "www"
6) "ddfff"
7) "qq"
8) "ll"
#在指定元素后插入新元素
127.0.0.1:6379> LINSERT mylist after ddfff eee
(integer) 9
127.0.0.1:6379> LRANGE mylist 0 -1
1) "ee"
2) "ww"
3) "nb"
4) "21"
5) "www"
6) "ddfff"
7) "eee"
8) "qq"
9) "ll"
删除数据
从列表左侧开始删除
LREM
127.0.0.1:6379> LRANGE mylist 0 -1
1) "we"
2) "fp"
3) "we"
4) "ed"
5) "we"
6) "om"
7) "we"
8) "ig"
9) "we"
10) "rn"
11) "we"
12) "df"
127.0.0.1:6379> LREM mylist 2 we #从列表左侧开始，删除2个we元素
(integer) 2
127.0.0.1:6379> LRANGE mylist 0 -1
1) "fp"
2) "ed"
3) "we"
4) "om"
5) "we"
6) "ig"
7) "we"
8) "rn"
9) "we"
10) "df"
修改数据
LSET
127.0.0.1:6379> LRANGE mylist 0 -1
1) "fp" #第0个元素
2) "ed" #第1个元素
3) "we" #第2个元素
4) "om"
5) "we"
6) "ig"
7) "we"
8) "rn"
9) "we"
10) "df"
#将第1个元素修改为clearlove7
127.0.0.1:6379> LSET mylist 1 clearlove7
OK
127.0.0.1:6379> LRANGE mylist 0 -1
1) "fp"
2) "clearlove7"
3) "we"
4) "om"
5) "we"
6) "ig"
7) "we"
8) "rn"
9) "we"
10) "df"
截取数据
LTRIM
127.0.0.1:6379> LRANGE mylist 0 -1
1) "fp"
2) "clearlove7"
3) "we"
4) "om"
5) "we"
6) "ig"
7) "we"
8) "rn"
9) "we"
10) "df"
#截取列表第1到第4个元素，替换源列表
127.0.0.1:6379> LTRIM mylist 1 4
OK
127.0.0.1:6379> LRANGE mylist 0 -1
1) "clearlove7"
2) "we"
3) "om"
4) "we"
查看列表
查看数据
LRANGE
#查看全部元素
127.0.0.1:6379> LRANGE mylist 0 -1
1) "clearlove7"
2) "we"
3) "om"
4) "we"
#查看第1到第2个元素
127.0.0.1:6379> LRANGE mylist 1 2
1) "we"
2) "om"
根据下标查看某个元素
LINDE
127.0.0.1:6379> LRANGE mylist 0 -1
1) "clearlove7"
2) "we"
3) "om"
4) "we"
127.0.0.1:6379> LINDEX mylist 0
"clearlove7"
查看列表长度
LLEN
127.0.0.1:6379> LRANGE mylist 0 -1
1) "clearlove7"
2) "we"
3) "om"
4) "we"
127.0.0.1:6379> LLEN mylist
(integer) 4
从左边查看并删除元素
LPOP
127.0.0.1:6379> LRANGE mylist 0 -1
1) "clearlove7"
2) "we"
3) "om"
4) "we"
127.0.0.1:6379> LPOP mylist
"clearlove7"
127.0.0.1:6379> LRANGE mylist 0 -1
1) "we"
2) "om"
3) "we"
从右边查看并删除元素
RPOP
127.0.0.1:6379> LRANGE mylist 0 -1
1) "we"
2) "om"
3) "we"
127.0.0.1:6379> RPOP mylist
"we"
127.0.0.1:6379> LRANGE mylist 0 -1
1) "we"
2) "om"
查看一个元素并移动到另一个列表中
RPOPLPUSH
127.0.0.1:6379> LRANGE mylist 0 -1
1) "11"
2) "10"
3) "01"
4) "00"
5) "we"
6) "om"
127.0.0.1:6379> LRANGE testlist 0 -1
1) "ff"
2) "dd"
127.0.0.1:6379> RPOPLPUSH mylist testlist
"om"
127.0.0.1:6379> RPOPLPUSH mylist testlist
"we"
127.0.0.1:6379> LRANGE mylist 0 -1
1) "11"
2) "10"
3) "01"
4) "00"
127.0.0.1:6379> LRANGE testlist 0 -1
1) "we"
2) "om"
3) "ff"
4) "dd"
BLPOP
从列表左侧开始查询，返回列表的key和左侧第一个元素
若查询的列表中没有元素，则原地阻塞至设置的timeout过后，返回空
若在阻塞状态时，列表新增了元素，则返回列表的key和左侧第一个元素，并删除该元素
#服务器A
#查询列表，此时列表为空，阻塞并等待100秒
127.0.0.1:6379> BLPOP testlist 100
#服务器B
#此时有人向列表插入新元素
127.0.0.1:6379> LPUSH testlist we
(integer) 1
#服务器A
#检测到新增元素，则返回列表的key和左侧第一个元素，并删除该元素
127.0.0.1:6379> BLPOP testlist 100
1) "testlist"
2) "we"
(22.24s)
#服务器B
#新增元素后查看，发现元素被删除
127.0.0.1:6379> LRANGE testlist 0 -1
(empty array)
