Redis list常用命令

什么是redis的list数据结构？

List类型是一个双端链表的结构，容量是2的32次方减1个元素，即40多亿个； 其主要功能有push、pop、获取元素等；一般应用在栈、队列、消息队列等场景。

Redis list命令实战

[LR]PUSH key value1 [value2 …]

以头插或尾插方式插入指定key队列中一个或多个元素

LRANGE key start stop

获取列表指定范围内的元素

127.0.0.1:6379> lpush products 1 2 3 (integer) 3 127.0.0.1:6379> lpush products 4 5 6 (integer) 6 127.0.0.1:6379> lrange products 0 -1 1) "6" 2) "5" 3) "4" 4) "3" 5) "2" 6) "1"

LINSERT key BEFORE|AFTER pivot value

在列表的元素前或者后插入元素

127.0.0.1:6379> lrange products 0 -1 1) "6" 2) "5" 3) "4" 4) "3" 5) "2" 6) "1" 127.0.0.1:6379> linsert products before 4 a (integer) 7 127.0.0.1:6379> lrange products 0 -1 1) "6" 2) "5" 3) "a" 4) "4" 5) "3" 6) "2" 7) "1" 127.0.0.1:6379> linsert products after 4 b (integer) 8 127.0.0.1:6379> lrange products 0 -1 1) "6" 2) "5" 3) "a" 4) "4" 5) "b" 6) "3" 7) "2" 8) "1"

LLEN key

获取列表长度

127.0.0.1:6379> lrange products 0 -1 1) "6" 2) "5" 3) "a" 4) "4" 5) "b" 6) "3" 7) "2" 8) "1" 127.0.0.1:6379> llen products (integer) 8

LINDEX key index

通过索引获取列表中的元素

127.0.0.1:6379> lrange products 0 -1 1) "6" 2) "5" 3) "a" 4) "4" 5) "b" 6) "3" 7) "2" 8) "1" 127.0.0.1:6379> lindex products 2 "a"

LSET key index value

通过索引设置列表元素的值

127.0.0.1:6379> lrange products 0 -1 1) "6" 2) "5" 3) "a" 4) "4" 5) "b" 6) "3" 7) "2" 8) "1" 127.0.0.1:6379> lset products 2 A OK 127.0.0.1:6379> lrange products 0 -1 1) "6" 2) "5" 3) "A" 4) "4" 5) "b" 6) "3" 7) "2" 8) "1"

LTRIM key start end

截取队列指定区间的元素,其余元素都删除

127.0.0.1:6379> lrange products 0 -1 1) "6" 2) "5" 3) "A" 4) "4" 5) "b" 6) "3" 7) "2" 8) "1" 127.0.0.1:6379> ltrim products 0 3 OK 127.0.0.1:6379> lrange products 0 -1 1) "6" 2) "5" 3) "A" 4) "4"

LREM key count value

移除列表元素

127.0.0.1:6379> lpush test a 1 a 2 a 3 a 4 5 6 (integer) 10 127.0.0.1:6379> lrange test 0 -1 1) "6" 2) "5" 3) "4" 4) "a" 5) "3" 6) "a" 7) "2" 8) "a" 9) "1" 10) "a" 127.0.0.1:6379> lrem test 4 a (integer) 4 127.0.0.1:6379> lrange test 0 -1 1) "6" 2) "5" 3) "4" 4) "3" 5) "2" 6) "1"

[LR]POP key

从队列的头或未弹出节点元素(返回该元素并从队列中删除)

127.0.0.1:6379> lrange test 0 -1 1) "6" 2) "5" 3) "4" 4) "3" 5) "2" 6) "1" 127.0.0.1:6379> lpop test "6" 127.0.0.1:6379> lrange test 0 -1 1) "5" 2) "4" 3) "3" 4) "2" 5) "1" 127.0.0.1:6379> lpop test "5" 127.0.0.1:6379> lrange test 0 -1 1) "4" 2) "3" 3) "2" 4) "1"

RPOPLPUSH source destination

移除列表的最后一个元素，并将该元素添加到另一个列表并返回

127.0.0.1:6379> lrange src 0 -1 1) "3" 2) "2" 3) "1" 127.0.0.1:6379> lrange dst 0 -1 1) "c" 2) "b" 3) "a" 127.0.0.1:6379> rpoplpush src dst "1" 127.0.0.1:6379> lrange src 0 -1 1) "3" 2) "2" 127.0.0.1:6379> lrange dst 0 -1 1) "1" 2) "c" 3) "b" 4) "a"

B[LR]POP key1 [key2 …] timeout

移出并获取列表的第一个或最后一个元素， 如果列表没有元素会阻塞列表直到等待超时或发现可弹出元素为止。

127.0.0.1:6379> lpush list1 1 2 (integer) 2 127.0.0.1:6379> lpush list2 a b (integer) 2 127.0.0.1:6379> lrange list1 0 -1 1) "2" 2) "1" 127.0.0.1:6379> lrange list2 0 -1 1) "b" 2) "a" 127.0.0.1:6379> blpop list1 list2 10 1) "list1" #弹出元素所属的列表 2) "2" #弹出元素所属的值 127.0.0.1:6379> blpop list1 list2 10 1) "list1" 2) "1" 127.0.0.1:6379> blpop list1 list2 10 1) "list2" 2) "b" 127.0.0.1:6379> blpop list1 list2 10 1) "list2" 2) "a" 127.0.0.1:6379> blpop list1 list2 10 (nil) (10.08s) # 列表为空的时候，就等待超时