decr
DECR
DECR key
Decrements the number stored at key
by one. If the key does not exist, it is set to 0
before performing the operation. An error is returned if the key contains a value of the wrong type or contains a string that can not be represented as integer. This operation is limited to 64 bit signed integers.
See INCR for extra information on increment-decrement operations-
Return value
Integer reply: the value of key
after the decrement