ZINTERSTORE

命令计算给定的一个或多个有序集的交集，其中给定 key 的数量必须以 numkeys 参数指定，并将该交集(结果集)储存到 destination 。

默认情况下，结果集中某个成员的分数值是所有给定集下该成员分数值之和。

ZINTERSTORE destination numkeys key [key ...] [WEIGHTS weight] [AGGREGATE SUM|MIN|MAX]

Command

$ redis-cli -h 127.0.0.1 -p 6379
127.0.0.1:6379> zadd z1 2 cat 3 dog
(integer) 2
127.0.0.1:6379> zadd z2 1 cat 4 goose
(integer) 2
// 返回交集里成员的数量。新集合中成员分数值默认是给定集合下成员分数值之和
127.0.0.1:6379> ZINTERSTORE z3 2 z1 z2
(integer) 1
127.0.0.1:6379> ZRANGE z3 0 -1 withscores
1) "cat"
2) "3"
// 使用权重时，也返回交集里成员的数量。默认依然是分数值相加，但是要先乘以权重值，此处即是2*1+1*2=4
127.0.0.1:6379> ZINTERSTORE z4 2 z1 z2 WEIGHTS 1 2
(integer) 1
127.0.0.1:6379> ZRANGE z4 0 -1 withscores
1) "cat"
2) "4"
// AGGREGATE包含SUM/MIN/MAX。ZINTERSTORE默认使用SUM。
// MIN即为取给定集合里最小的分数值，MAX则反之
127.0.0.1:6379> ZINTERSTORE z5 2 z1 z2 AGGREGATE MIN
(integer) 1
127.0.0.1:6379> ZRANGE z5 0 -1 withscores
1) "cat"
2) "1"
127.0.0.1:6379> ZINTERSTORE z6 2 z1 z2 AGGREGATE MAX
(integer) 1
127.0.0.1:6379> ZRANGE z6 0 -1 withscores
1) "cat"
2) "2"
//AGGREGATE和权重WEIGHTS一起使用时，取经过权重计算后的结果
//此处即2*3>1*4
127.0.0.1:6379> ZINTERSTORE z7 2 z1 z2 WEIGHTS 3 4 AGGREGATE MAX
(integer) 1
127.0.0.1:6379> ZRANGE z7 0 -1 withscores
1) "cat"
2) "6"

Code

func zinterstore(c redis.Conn) {
    defer c.Do("DEL", "z1", "z2", "z3", "z4", "z5", "z6", "z7")
    c.Do("ZADD", "z1", 2, "cat", 3, "dog")
    c.Do("ZADD", "z2", 1, "cat", 4, "goose")
    //  Return numbers of members in intersection.
    //  1. Score of members in new sorted set is sum of score of members in specified sorted sets as default.
    numOfMembersInIntersection, _ := c.Do("ZINTERSTORE", "z3", 2, "z1", "z2")
    fmt.Println("numbers of members in intersection:", numOfMembersInIntersection)
    membersAndScores, _ := redis.Strings(c.Do("ZRANGE", "z3", 0, -1, "withscores"))
    for i, v := range membersAndScores {
        if i%2 == 0 {
            fmt.Println("Member", i/2, "is:", v)
        } else {
            fmt.Println("Score of member", (i-1)/2, "is:", v)
        }
    }
    //  2. If use weights, Score of members in new sorted set is sum of score of members in specified sorted sets
    //  multiplied by the weight. Here is 2*1+1*2=4.
    numOfMembersInIntersection, _ = c.Do("ZINTERSTORE", "z4", 2, "z1", "z2", "WEIGHTS", 1, 2)
    fmt.Println("numbers of members in intersection when use weights:", numOfMembersInIntersection)
    membersAndScores, _ = redis.Strings(c.Do("ZRANGE", "z4", 0, -1, "withscores"))
    for i, v := range membersAndScores {
        if i%2 == 0 {
            fmt.Println("Member", i/2, "is:", v)
        } else {
            fmt.Println("Score of member", (i-1)/2, "is:", v)
        }
    }
    //  3. AGGREGATE option include SUM/MIN/MAX. ZINTERSTORE use SUM as default.
    //  MIN means the score of members in new sorted set is the min score of members in specified sorted sets.
    numOfMembersInIntersection, _ = c.Do("ZINTERSTORE", "z5", 2, "z1", "z2", "AGGREGATE", "MIN")
    fmt.Println("numbers of members in intersection when use AGGREGATE MIN:", numOfMembersInIntersection)
    membersAndScores, _ = redis.Strings(c.Do("ZRANGE", "z5", 0, -1, "withscores"))
    for i, v := range membersAndScores {
        if i%2 == 0 {
            fmt.Println("Member", i/2, "is:", v)
        } else {
            fmt.Println("Score of member", (i-1)/2, "is:", v)
        }
    }
    //  MAX means the score of members in new sorted set is the max score of members in specified sorted sets.
    numOfMembersInIntersection, _ = c.Do("ZINTERSTORE", "z6", 2, "z1", "z2", "AGGREGATE", "MAX")
    fmt.Println("numbers of members in intersection when use AGGREGATE MAX:", numOfMembersInIntersection)
    membersAndScores, _ = redis.Strings(c.Do("ZRANGE", "z6", 0, -1, "withscores"))
    for i, v := range membersAndScores {
        if i%2 == 0 {
            fmt.Println("Member", i/2, "is:", v)
        } else {
            fmt.Println("Score of member", (i-1)/2, "is:", v)
        }
    }
    //  4. If use both AGGREGATE and WEIGHTS, the score of members in new sorted set is the result of the scores of
    //  members in specified sorted sets multiplied by the weight.
    //  Here the max value is 6, that is 2*3 > 1*4
    numOfMembersInIntersection, _ = c.Do("ZINTERSTORE", "z7", 2, "z1", "z2",
        "WEIGHTS", 3, 4, "AGGREGATE", "MAX")
    fmt.Println("numbers of members in intersection when use both WEIGHTS and AGGREGATE MAX:",
        numOfMembersInIntersection)
    membersAndScores, _ = redis.Strings(c.Do("ZRANGE", "z7", 0, -1, "withscores"))
    for i, v := range membersAndScores {
        if i%2 == 0 {
            fmt.Println("Member", i/2, "is:", v)
        } else {
            fmt.Println("Score of member", (i-1)/2, "is:", v)
        }
    }
}

Output

$ go run main.go 
numbers of members in intersection: 1
Member 0 is: cat
Score of member 0 is: 3
numbers of members in intersection when use weights: 1
Member 0 is: cat
Score of member 0 is: 4
numbers of members in intersection when use AGGREGATE MIN: 1
Member 0 is: cat
Score of member 0 is: 1
numbers of members in intersection when use AGGREGATE MAX: 1
Member 0 is: cat
Score of member 0 is: 2
numbers of members in intersection when use both WEIGHTS and AGGREGATE MAX: 1
Member 0 is: cat
Score of member 0 is: 6