redis lrem命令

LREM key count value

Removes the first count occurrences of elements equal to value from the list stored at key. The count argument influences the operation in the following ways:

  • count > 0: Remove elements equal to value moving from head to tail.
  • count < 0: Remove elements equal to value moving from tail to head.
  • count = 0: Remove all elements equal to value.

For example, LREM list -2 "hello" will remove the last two occurrences of "hello" in the list stored at list.

Note that non-existing keys are treated like empty lists, so when key does not exist, the command will always return 0.

*返回值

Integer reply: the number of removed elements.

*例子

redis>  RPUSH mylist “hello”
(integer) 1
redis>  RPUSH mylist “hello”
(integer) 2
redis>  RPUSH mylist “foo”
(integer) 3
redis>  RPUSH mylist “hello”
(integer) 4
redis>  LREM mylist -2 “hello”
(integer) 2
redis>  LRANGE mylist 0 -1
1) "hello"
2) "foo"
redis>