.0.1:6379> hincrby product price -100
(integer) 3300 # price减去100
11，hdel 命令：
hdel [...] 删除hash表中key的一个或者多个域的值。如果指定的field不存在，则忽略操作。
[plain]
redis 127.0.0.1:6379> hgetall product
1) "name"
2) "computer"
3) "price"
4) "3300"
5) "size"
6) "14inch"
7) "final"
8) "3200"
redis 127.0.0.1:6379> hdel product size
(integer) 1
redis 127.0.0.1:6379> hgetall product
1) "name"
2) "computer"
3) "price"
4) "3300"
5) "final"
6) "3200"
redis 127.0.0.1:6379> hdel product final price
(integer) 2
redis 127.0.0.1:6379> hgetall product
1) "name"
2) "computer"