ZRANGE && ZREVRANGE

ZRANGE && ZREVRANGE

• 返回有序集中，指定区间内的成员。其中成员的位置按分数值递增(从小到大/从大到小)来排序。
• 使用ZRANGE时，具有相同分数值的成员按字典序(lexicographical order)来排列。
• 使用ZREVRANGE时，具有相同分数值的成员按字典序的逆序(reverse lexicographical order)来排列。

Command

$ redis-cli -h 127.0.0.1 -p 6379
127.0.0.1:6379> zrange s2 0 -1
(empty list or set)
127.0.0.1:6379> ZADD fruit 1 cherry 2 plum 2 pear 3 grape
(integer) 4
127.0.0.1:6379> ZRANGE fruit 0 -1 WITHSCORES
1) "cherry"
2) "1"
3) "pear"
4) "2"
5) "plum"
6) "2"
7) "grape"
8) "3"
127.0.0.1:6379> ZREVRANGE fruit 0 -1 WITHSCORES
1) "grape"
2) "3"
3) "plum"
4) "2"
5) "pear"
6) "2"
7) "cherry"
8) "1"

Code

ZREVRANGE就只是ZRANGE相反，此处便不用代码示例

func zrange(c redis.Conn) {
    defer c.Do("DEL", "fruit")
    c.Do("ZADD", "fruit", 1, "cherry", 2, "plum", 2, "pear", 3, "grape")
    membersWithScore, _ := redis.Strings(c.Do("ZRANGE", "fruit", 0, -1, "WITHSCORES"))
    fmt.Println("If some members' scores are same, will sort them by lexicographical order.")
    for i, v := range membersWithScore {
        if i%2 == 0 {
            fmt.Println("member is:", v)
        } else {
            fmt.Println("Score is:", v)
        }
    }
}

Output

$ go run main.go
If some members' scores are same, will sort them by lexicographical order.
member is: cherry
Score is: 1
member is: pear
Score is: 2
member is: plum
Score is: 2
member is: grape
Score is: 3