GETSET key value
value and returns the old value stored at
key. Returns an error when
key exists but does not hold a string value.
GETSET can be used together with INCR for counting with atomic reset. For example: a process may call INCR against the key
mycounter every time some event occurs, but from time to time we need to get the value of the counter and reset it to zero atomically. This can be done using
GETSET mycounter "0":
(integer) 1redis> GETSET mycounter “0”
"1"redis> GET mycounter
Bulk string reply: the old value stored at
key did not exist.
"OK"redis> GETSET mykey “World”
"Hello"redis> GET mykey