[大数据]Redis之Hash（哈希）

Map集合，key-map!这时候的集合是Map集合！本质和String，类型没有太大区别，还是一个简单的Key-value!
set myhash field lilin

127.0.0.1:6379> hset myhash field1 lilin #set一个具体的key-value
(integer) 1
127.0.0.1:6379> hget myhash field1 #获取多个值
"lilin"
127.0.0.1:6379> hmset myhash field1 hello field2 world #set多个key-value
OK
127.0.0.1:6379> hmget myhash field2 fiedl2 #获取多个字段值
1) "world"
2) (nil)
127.0.0.1:6379> hmget myhash field2 fiedl1
1) "world"
2) (nil)
127.0.0.1:6379> hmget myhash field1 field2
1) "hello"
2) "world"
127.0.0.1:6379> hgetall myhash #获取全部的数据，
1) "field1"
2) "hello"
3) "field2"
4) "world"
127.0.0.1:6379> 
127.0.0.1:6379> hdel myhash field1 #删除hash指定的key字段！对应的value值也就没有了
(integer) 1
127.0.0.1:6379> hgetall myhash
1) "field2"
2) "world"
127.0.0.1:6379> 

hexists：判断hash中指定字段是否存在！

127.0.0.1:6379> hexists myhash field2
(integer) 1
127.0.0.1:6379> 

#只获得所有field
#只获得所有value

127.0.0.1:6379> hkeys myhash #只获得所有field
1) "field2"
127.0.0.1:6379> hvals myhash #只获得所有value
1) "world"
127.0.0.1:6379> 

127.0.0.1:6379> hset myhash field3 5 #指定增量
(integer) 1
127.0.0.1:6379> HINCRBY myhash field3 1
(integer) 6
127.0.0.1:6379> HINCRBY myhash field3 1
(integer) 7
127.0.0.1:6379> HINCRBY myhash field3 -1 
(integer) 6
127.0.0.1:6379> hsetnx myhash field4 ll
(integer) 1
127.0.0.1:6379> 

Hash变更得数据user name age ,尤其是用户信息之类得，经常变动的信息！,hash更适合于对象的存储，String更佳适合字符串存储！