Redis list 之增删改查

àì夳堔傛蜴生んèń 2022-05-08 11:12 249阅读 0赞

一、增加

1、lpush \[lpush key valus...\]  类似于压栈操作，将元素放入头部

127.0.0.1:6379> lpush plist ch0 ch1 ch2
    (integer) 3
    127.0.0.1:6379> lrange plist 0 3
    1) "ch2"
    2) "ch1"
    3) "ch0"
    127.0.0.1:6379> lpush plist ch4
    (integer) 4
    127.0.0.1:6379> lrange plist 0 4
    1) "ch4"
    2) "ch2"
    3) "ch1"
    4) "ch0"

2 、lpushx \[lpushx key valus\]:只能插入已经存在的key,且一次只能插入一次

127.0.0.1:6379> lpushx pl ch
    (integer) 0
    127.0.0.1:6379> lpushx plist ch5 ch6
    (error) ERR wrong number of arguments for 'lpushx' command
    127.0.0.1:6379> lpushx plist ch5
    (integer) 5
    127.0.0.1:6379> lrange plist 0 5
    1) "ch5"
    2) "ch4"
    3) "ch2"
    4) "ch1"
    5) "ch0"

3、rpush  \[rpush key valus...\] ：将元素push在list的尾部

127.0.0.1:6379> rpush plist ch6
    (integer) 6
    127.0.0.1:6379> lrange plist 0 6
    1) "ch5"
    2) "ch4"
    3) "ch2"
    4) "ch1"
    5) "ch0"
    6) "ch6"
    127.0.0.1:6379> rpush plist ch7 ch8
    (integer) 8
    127.0.0.1:6379> lrange plist 0 8
    1) "ch5"
    2) "ch4"
    3) "ch2"
    4) "ch1"
    5) "ch0"
    6) "ch6"
    7) "ch7"
    8) "ch8"

4、rpushx \[rpushx key valus...\] :相对于lpushx

5、linsert \[linsert key before/after pivot value\]:将值插入到pivot的前面或后面。返回列表元素个数。如果参照点pivot不存在不插入。如果有多个pivot，以离表头最近的为准

127.0.0.1:6379> linsert plist before ch1 chi
    (integer) 9
    127.0.0.1:6379> lrange plist 0 9
    1) "ch5"
    2) "ch4"
    3) "ch2"
    4) "chi"
    5) "ch1"
    6) "ch0"
    7) "ch6"
    8) "ch7"
    9) "ch8"
    127.0.0.1:6379> linsert plist before chii chi2
    (integer) -1
    127.0.0.1:6379> linsert plist after chi cha
    (integer) 10
    127.0.0.1:6379> lrange plist 0 10
     1) "ch5"
     2) "ch4"
     3) "ch2"
     4) "chi"
     5) "cha"
     6) "ch1"
     7) "ch0"
     8) "ch6"
     9) "ch7"
    10) "ch8"

![复制代码][copycode.gif]

//以上插入操作均是返回list的长度

二、删除

1、lpop 、rpop：分别为删除头部和尾部，返回被删除的元素

![复制代码][copycode.gif]

127.0.0.1:6379> lpop plist
    "ch5"
    127.0.0.1:6379> lrange plist 0 10
    1) "ch4"
    2) "ch2"
    3) "chi"
    4) "cha"
    5) "ch1"
    6) "ch0"
    7) "ch6"
    8) "ch7"
    9) "ch8"
    127.0.0.1:6379> rpop plist
    "ch8"
    127.0.0.1:6379> lrange plist 0 10
    1) "ch4"
    2) "ch2"
    3) "chi"
    4) "cha"
    5) "ch1"
    6) "ch0"
    7) "ch6"
    8) "ch7"

![复制代码][copycode.gif]

2 、ltrim \[ltrim key  range\_l range\_r\]:保留区域类的元素，其他的删除

![复制代码][copycode.gif]

127.0.0.1:6379> ltrim plist 0 3
    OK
    127.0.0.1:6379> lrange plist 0 10
    1) "ch4"
    2) "ch2"
    3) "chi"
    4) "cha"

![复制代码][copycode.gif]

3、lrem \[lrem key count value\] :移除等于value的元素，当count>0时，从表头开始查找，移除count个；当count=0时，从表头开始查找，移除所有等于value的；当count<0时，从表尾开始查找，移除|count| 个。

cout >0

![复制代码][copycode.gif]

127.0.0.1:6379> lrange plist 0 10
     1) "ch0"
     2) "ch0"
     3) "ch0"
     4) "ch4"
     5) "chi"
     6) "cha"
     7) "ch0"
     8) "ch0"
     9) "ch0"
    10) "ch0"
    127.0.0.1:6379> lrem plist 5 ch0
    (integer) 5
    127.0.0.1:6379> lrange plist 0 10
    1) "ch4"
    2) "chi"
    3) "cha"
    4) "ch0"
    5) "ch0"

![复制代码][copycode.gif]

count <0

![复制代码][copycode.gif]

127.0.0.1:6379> lrange plist 0 10
     1) "ch0"
     2) "ch9"
     3) "ch0"
     4) "ch0"
     5) "ch0"
     6) "ch4"
     7) "chi"
     8) "cha"
     9) "ch0"
    10) "ch0"
    127.0.0.1:6379> lrem plist -5 ch0
    (integer) 5
    127.0.0.1:6379> lrange plist 0 10
    1) "ch0"
    2) "ch9"
    3) "ch4"
    4) "chi"
    5) "cha"

![复制代码][copycode.gif]

三、修改  
lset \[lset key index value\] : 设置列表指定索引的值，如果指定索引不存在则报错

![复制代码][copycode.gif]

127.0.0.1:6379> lset plist 0 ch2
    OK
    127.0.0.1:6379> lrange plist 0 10
    1) "ch2"
    2) "ch9"
    3) "ch4"
    4) "chi"
    5) "cha"

![复制代码][copycode.gif]

四、查询  
1、lindex \[lindex key index\]:通过索引index获取列表的元素、key>=0从头到尾，key<0从尾到头

![复制代码][copycode.gif]

127.0.0.1:6379> lrange plist 0 10
    1) "ch2"
    2) "ch9"
    3) "ch4"
    4) "chi"
    5) "cha"
    127.0.0.1:6379> lindex plist 0
    "ch2"
    127.0.0.1:6379> lindex plist -0
    "ch2"
    127.0.0.1:6379> lindex plist -1
    "cha"
    127.0.0.1:6379> lindex plist 5
    (nil)

![复制代码][copycode.gif]

2、lrange \[lrange key range\_l range\_r\]:0 表头、-1表尾

[copycode.gif]: /images/20220508/b6591a5a59044cc192c6acb6f6bd1cc0.png