无hash时，用键值对
set six::name "6"
get six::name
set six::age 18
get six::age
keys six * ==> six::name six::age
有hash时
hset six name yyds
hmset six age 18 address bj
hget six name "yyds"
hget six age "18"
hmget six name age "yyds" "18"
hkeys six "name" "age" "address"
hvals six "yyds" "18" "bj"
hgetall six "name" "yyds" "age" "18" "address" "bj"
hincrbyfloat six age 0.5
hget six age "18.5"
hincrbyfloat six age -1
hget six age "17.5"