Redis学习笔记3--Redis键值设计

tag在互联网应用里尤其多见，首先看下面的关系型数据表：

Book表： 

id	name	author
1	The Ruby Programming Language	Mark Pilgrim
2	Ruby on rail	David Flanagan
3	Programming Erlang	Joe Armstrong

Tag表：

tag_name	book_id
ruby	1
ruby	2
web	2
erlang	3

 

现在用redis将这两张表的数据存起来： 

保存Book的数据：

redis 127.0.0.1:6379> incr book_id #用book_id这个key保存book表的id,每次要获得一个新的                                           #book_id用incr命令自增取得 (integer) 1 #incr命令返回1,则用key为book:1的hash来保存一个book对象,对象属性为hash的field redis 127.0.0.1:6379> hset book:1 name "The Ruby Programming Language" (integer) 1 redis 127.0.0.1:6379> hset book:1 author "Mark Pilgrim" (integer) 1 redis 127.0.0.1:6379> hgetall book:1 #用hgetall命令测试一个,返回hash的所有属性和值 1) "name" 2) "The Ruby Programming Language" 3) "author" 4) "Mark Pilgrim" redis 127.0.0.1:6379> incr book_id #创建第2个book对象,先incr一个book_id获得新book的id (integer) 2 redis 127.0.0.1:6379> hset book:2 name "Ruby on rail" (integer) 1 redis 127.0.0.1:6379> hset book:2 author "David Flanagan" (integer) 1 redis 127.0.0.1:6379> hgetall book:2 1) "name" 2) "Ruby on rail" 3) "author" 4) "David Flanagan" redis 127.0.0.1:6379> incr book_id (integer) 3 redis 127.0.0.1:6379> hset book:3 name "Programming Erlang" (integer) 1 redis 127.0.0.1:6379> hset book:3 author "Joe Armstrong" (integer) 1 redis 127.0.0.1:6379> hgetall book:3 1) "name" 2) "Programming Erlang" 3) "author" 4) "Joe Armstrong"

 

保存Tag的数据，使用集合来存储数据，因为集合可以求交集、并集、差集：

redis 127.0.0.1:6379> sadd tag:ruby 1 (integer) 1 redis 127.0.0.1:6379> sadd tag:ruby 2 (integer) 1 redis 127.0.0.1:6379> sadd tag:web 2 (integer) 1 redis 127.0.0.1:6379> sadd tag:erlang 3 (integer) 1

 

如果要取得即属于ruby又属于web的书：

redis 127.0.0.1:6379> sinter tag:ruby tag:web 1) "2"

如果要取得属于ruby，但不属于web的书：

redis 127.0.0.1:6379> sdiff tag:ruby tag:web 1) "1"

属于ruby和属于web的书的合集：

redis 127.0.0.1:6379> sunion tag:ruby tag:web 1) "1" 2) "2"