Redis DECRBY command is used to decrement the number stored at the key by the specified value. 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 cannot be represented as an integer.
Integer reply, the value of the key after the increment.
Following is the basic syntax of Redis DECRBY command.
redis 127.0.0.1:6379> DECRBY KEY_NAME DECREMENT_AMOUNT
redis 127.0.0.1:6379> SET visitors 1000 OK redis 127.0.0.1:6379> DECRBY visitors 5 (integer) 995