Redis DECR command is used to decrement the integer value of a 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 cannot be represented as an integer. This operation is limited to 64 bit signed integers.
Integer reply, the value of the key after the increment.
Following is the basic syntax of Redis DECR command.
redis 127.0.0.1:6379> DECR KEY_NAME
redis 127.0.0.1:6379> SET visitors 1000 OK redis 127.0.0.1:6379> DECR visitors (integer) 999 redis 127.0.0.1:6379> SET visitors "13131312312312312312312rgergerg" Ok redis 127.0.0.1:6379> DECR visitors ERR value is not an integer or out of range