006_ redis_ Sortedset type

006_redis_SortedSet type

1、 It's a sortable set aggregate , And java Medium treeset similar . But the underlying data structure is very different .

• SortedSet Each element in the has a score Properties of , Can be based on score Attribute to sort elements
• The underlying implementation is a jump table （SkipList） Add hash surface

2、SortedSet Have the characteristics of

• disorder
• Element is not repeatable
• Fast query speed

 summary ： because SortedSet SORTABILITY of , Often used to implement functions such as ranking boards .

3、SortedSet Common types of commands

• ZADD: Add one or more elements
• ZREM： Delete a specified element
• ZSCORE： Gets the amount of the specified element in the collection score value
• ZRANK： Gets the sort of the specified element
• ZCARD： Get the number of elements in the collection
• ZCOUNT： Statistics score The number of all elements whose values are within a given range
• ZINCREBY： Specified element self increment
• ZRANGE： according to score After sorting , Get the elements within the specified ranking range
• ZDIFF、ZINTER、ZUNION： Difference set 、 intersection 、 Combine

 
  Be careful ： All rankings are in ascending order by default , If you need to set the descending operation , Need to be in Z Add later REV that will do . such as ：ZREVRANK

（1） Test practice

127.0.0.1:6379> zadd stus 85 jack 89 lucy 82 rose 95 tom 78 jerry 76 Miles
(integer) 6
127.0.0.1:6379> zrem stus tom
(integer) 1

• obtain rose The ranking of students
  The ranking returned is from 0 At the beginning .

127.0.0.1:6379> zrank stus rose
(integer) 2
127.0.0.1:6379> zrevrank stus rose
(integer) 2

• Inquire about 80 How many people are there

127.0.0.1:6379> zcount stus 0 80
(integer) 2

• to Rose Classmate plus 2 branch

127.0.0.1:6379> zincrby stus 2 rose
"84"

• Find out the top three students （ Default ascending order , It needs to be reversed rev）

127.0.0.1:6379> zrevrange stus 0 2
1) "lucy"
2) "jack"
3) "rose"

• Find out the results 80 All the students below

127.0.0.1:6379> zrangebyscore stus 0 80
1) "Miles"
2) "jerry"