Redis(3)Redis Data Type and Specialty
Redis(3)Redis Data Type and Specialty

1. Sorted Set Type
Almost the same as Set, but we can use a key score to order our data.
> zadd days 0 mon
(integer) 1
> zadd days 1 tue
(integer) 1
> zadd days 2 wed
(integer) 1
> zadd days 3 thu
(integer) 1
> zadd days 4 fri
(integer) 1
> zadd days 5 sat
(integer) 1
> zadd days 6 sun
(integer) 1
> zcard days
(integer) 7
> zrange days 0 6
1) "mon"
2) "tue"
3) "wed"
4) "thu"
5) "fri"
6) "sat"
7) "sun"
> zscore days sat
"5"
> zscore days mon
"0"
> zrangebyscore days 3 6
1) "thu"
2) "fri"
3) "sat"
4) "sun"

2. Hash Type
> hmset user1 username tester password 111111 age 30 gender 1
OK
> hgetall user1
1) "username"
2) "tester"
3) "password"
4) "111111"
5) "age"
6) "30"
7) "gender"
8) "1"
> hset user1 password 12345
(integer) 0
> hgetall user1
1) "username"
2) "tester"
3) "password"
4) "12345"
5) "age"
6) "30"
7) "gender"
8) "1"
> hkeys user1
1) "username"
2) "password"
3) "age"
4) "gender"
> hvals user1
1) "tester"
2) "12345"
3) "30"
4) "1"
> hdel user1 gender
(integer) 1
> hgetall user1
1) "username"
2) "tester"
3) "password"
4) "12345"
5) "age"
6) "30"

> HMSET kid-001 name Akshi age 2 sex Female
OK
> hmget kid-001 age name
1) "2"
2) "Akshi"

3. Publish/Subscribe
You can publish the data to one pipeline, others can subscribe these data.
One client can subscribe the channel
> subscribe ccav
Reading messages... (press Ctrl-C to quit)
1) "subscribe"
2) "ccav"
3) (integer) 1
1) "message"
2) "ccav"
3) "news1"
1) "message"
2) "ccav"
3) "news2"

The other client can publish the message
> publish ccav news1
(integer) 1
> publish ccav news2
(integer) 1

And we can subscribe a set of channels like this:
> psubscribe cc*
Reading messages... (press Ctrl-C to quit)
1) "psubscribe"
2) "cc*"
3) (integer) 1
1) "pmessage"
2) "cc*"
3) "cctv"
4) "news3"
1) "pmessage"
2) "cc*"
3) "ccav"
4) "news2"

> publish cctv news3
(integer) 1
> publish ccav news2
(integer) 1

4. Data Expiration
> set name "sillycat"
OK

ttl can check the expiration time, -1 means never.
> ttl name
(integer) -1

> exists name
(integer) 1

expire command can set the key=name with expiration time 5 seconds
> expire name 5
(integer) 1
> exists name
(integer) 0

There is also a command expireat, but I did not try that.

5. Check Suffix Command
NX will check if the key does not exist, then we will proceed the command.

> set name "karl"
OK
> setnx name "peter"
(integer) 0
> get name
"karl"

6. Other Operations
There is default 16 database in redis, we can select different databases as follow:
> select 0
OK
> set name karl
OK
> select 1
OK
>[1set name karl1
OK
>[1get name
"karl1"
>[1select 0
OK
> get name
"karl"

references:
http://blog.nosqlfan.com/html/3139.html
http://redis.io/topics/data-types