redis学习笔记（四）

list（数组）

队列，列表的子成员类型为string

lpush key value

rpush key value

linsert key after|before 指定元素 value

lindex key index

lrange key start stop

lset key index value

lrem key count value

127.0.0.1:6379> lpush names ww zs ls
(integer) 3
127.0.0.1:6379> type names
list
127.0.0.1:6379> lrange names 0 -1
1) "ls"
2) "zs"
3) "ww"
127.0.0.1:6379> rpush names a b c
(integer) 6
127.0.0.1:6379> lrange names 0 -1
1) "ls"
2) "zs"
3) "ww"
4) "a"
5) "b"
6) "c"
127.0.0.1:6379> lpush names x y
(integer) 8
127.0.0.1:6379> lrange names 0 -1
1) "y"
2) "x"
3) "ls"
4) "zs"
5) "ww"
6) "a"
7) "b"
8) "c"

（1）添加子成员

# 在左侧(前)添加一条或多条数据
lpush key value1 value2 ...
# 在右侧(后)添加一条或多条数据
rpush key value1 value2 ...# 在指定元素的左边(前)/右边（后）插入一个或多个数据
linsert key before 指定元素 value1 value2 ....
linsert key after 指定元素 value1 value2 ....

从键为brother的列表左侧添加一个或多个数据liubei、guanyu、zhangfei

lpush brother liubei
# [liubei]
lpush brother guanyu zhangfei xiaoming
# [xiaoming,zhangfei,guanyu,liubei]

从键为brother的列表右侧添加一个或多个数据，xiaohong,xiaobai,xiaohui

rpush brother xiaohong
# [xiaoming,zhangfei,guanyu,liubei,xiaohong]
rpush brother xiaobai xiaohui
# [xiaoming,zhangfei,guanyu,liubei,xiaohong,xiaobai,xiaohui]

从key=brother的xiaohong的列表位置左侧添加一个数据，xiaoA,xiaoB

linsert brother before xiaohong xiaoA
# [xiaoming,zhangfei,guanyu,liubei,xiaoA,xiaohong,xiaobai,xiaohui]
linsert brother before xiaohong xiaoB
# [xiaoming,zhangfei,guanyu,liubei,xiaoA,xiaoB,xiaohong,xiaobai,xiaohui]

从key=brother，key=xiaohong的列表位置右侧添加一个数据，xiaoC,xiaoD

linsert brother after xiaohong xiaoC
# [xiaoming,zhangfei,guanyu,liubei,xiaoA,xiaohong,xiaoC,xiaobai,xiaohui]
linsert brother after xiaohong xiaoD
# [xiaoming,zhangfei,guanyu,liubei,xiaoA,xiaohong,xiaoD,xiaoC,xiaobai,xiaohui]

注意：当列表如果存在多个成员值一致的情况下，默认只识别第一个。

127.0.0.1:6379> linsert brother before xiaoA xiaohong
# [xiaoming,zhangfei,guanyu,liubei,xiaohong,xiaoA,xiaohong,xiaoD,xiaoC,xiaobai,xiaohui]
127.0.0.1:6379> linsert brother before xiaohong xiaoE
# [xiaoming,zhangfei,guanyu,liubei,xiaoE,xiaohong,xiaoA,xiaohong,xiaoD,xiaoC,xiaobai,xiaohui]
127.0.0.1:6379> linsert brother after xiaohong xiaoF
# [xiaoming,zhangfei,guanyu,liubei,xiaoE,xiaohong,xiaoF,xiaoA,xiaohong,xiaoD,xiaoC,xiaobai,xiaohui]

（2）基于索引获取列表成员

根据指定的索引(下标)获取成员的值，负数下标从右边-1开始，逐个递减

lindex key index

获取brother下标为2以及-2的成员

del brother
lpush brother guanyu zhangfei xiaoming
lindex brother 2
# "guanyu"
lindex brother -2
# "zhangfei"

（3）获取列表的切片

闭区间[包括stop]

lrange key start stop

操作：

del brother
rpush brother liubei guanyu zhangfei xiaoming xaiohong
# 获取btother的全部成员
lrange brother 0 -1
# 获取brother的前2个成员
lrange brother 0 1
# 获取brother的后2个成员
lrange brother -2 -1

127.0.0.1:6379> linsert names after "y" 10
(integer) 9
127.0.0.1:6379> lrange names 0 -1
1) "y"
2) "10"
3) "x"
4) "ls"
5) "zs"
6) "ww"
7) "a"
8) "b"
9) "c"127.0.0.1:6379> linsert names before "y" 20
(integer) 10
127.0.0.1:6379> lrange names 0 -11) "20"2) "y"3) "10"4) "x"5) "ls"6) "zs"7) "ww"8) "a"9) "b"
10) "c"127.0.0.1:6379> lindex names 3
"x"
127.0.0.1:6379> lindex names 0
"20"
127.0.0.1:6379> lindex names -1
"c"127.0.0.1:6379> lrange names 0 1
1) "20"
2) "y"
127.0.0.1:6379> lrange names -2 -1
1) "b"
2) "c"
127.0.0.1:6379>

（4）获取列表的长度

llen key

获取brother列表的成员个数

llen brother

（5）按索引设置值

lset key index value
# 注意：
# redis的列表也有索引，从左往右，从0开始，逐一递增，第1个元素下标为0
# 索引可以是负数，表示尾部开始计数，如`-1`表示最后1个元素

修改键为brother的列表中下标为4的元素值为xiaohongmao

lset brother 4 xiaohonghong

（6）删除指定成员

移除并获取列表的第一个成员或最后一个成员

lpop key  # 第一个成员出列
rpop key  # 最后一个成员出列

获取并移除brother中的第一个成员

lpop brother
# 开发中往往使用rpush和lpop实现队列的数据结构->实现入列和出列

lrem key count value# 注意：
# count表示删除的数量，value表示要删除的成员。该命令默认表示将列表从左侧前count个value的元素移除
# count==0，表示删除列表所有值为value的成员
# count >0，表示删除列表左侧开始的前count个value成员
# count <0，表示删除列表右侧开始的前count个value成员del brother
rpush brother A B A C A
lrem brother 0 A
["B","C"]del brother
rpush brother A B A C A
lrem brother -2 A
["A","B","C"]del brother
rpush brother A B A C A
lrem brother 2 A
["B","C","A"]

127.0.0.1:6379> llen names
(integer) 10
127.0.0.1:6379> lset names 9 cc
OK
127.0.0.1:6379> lrange names 0 -11) "20"2) "y"3) "10"4) "x"5) "ls"6) "zs"7) "ww"8) "a"9) "b"
10) "cc"
127.0.0.1:6379> lpop names
"20"
127.0.0.1:6379> lrange names 0 -1
1) "y"
2) "10"
3) "x"
4) "ls"
5) "zs"
6) "ww"
7) "a"
8) "b"
9) "cc"127.0.0.1:6379> rpop names
"cc"
127.0.0.1:6379> lrange names 0 -1
1) "y"
2) "10"
3) "x"
4) "ls"
5) "zs"
6) "ww"
7) "a"
8) "b"
127.0.0.1:6379> rpush namaes x
(integer) 1
127.0.0.1:6379> lrange names 0 -1
1) "y"
2) "10"
3) "x"
4) "ls"
5) "zs"
6) "ww"
7) "a"
8) "b"
127.0.0.1:6379> rpush names x
(integer) 9
127.0.0.1:6379> lrange namaes 0 -1
1) "x"
127.0.0.1:6379> lrem names -1 x
(integer) 1
127.0.0.1:6379> lrange names 0 -1
1) "y"
2) "10"
3) "x"
4) "ls"
5) "zs"
6) "ww"
7) "a"
8) "b"
127.0.0.1:6379>