The last post is mainly about the unsorted set,in this post I will show you the sorted set playing an important
role in Redis.There are many command added after the version 2.8.9.OK,let's see the below picture firstly.There
are 24 commands to handle the sorted set,the same as the string.
Many commands are similar with the Set.Both of them are the set,the sorted set's member has a score
playing a important role on sorting.We can use the zadd to store the sorted set.The following example demonstrates
the usage of zadd.
zadd set- a
zadd set- b c d e f g h i j k
For learning how many elements in the set,and who are them ? we can use the command zrange.
zrange set- -
zrange can also make us know the scores of the elements,we should open seletion the withscores to
find out their scores.
zrange set- - withscores
There are another intresting commands to get the members.zrangebyscore can find out the members by
their scores.For an instance,I want to find out the members' scores between 0 and 6,so I will use zrangebyscore set-
to finish this job.zrangebylex can find out the members by the lexicographical order when some of them are in
the same scores.Now I want to find out the members that order by lexicography when the score are the same
while in the range (a,k],so using zrangebylex set- (a [k can easily do this job.
We also can know the rank of a member.both Ascending and Descending.For ascending,we use zrank.For descending
we use zrevrank .For example ,we want to know the member d's rank.
zrank set- d
zrevrank set- d
There are also many command that we can use to remove the member from the set.Using zrem to remove one or
more members,Using zremrangebyrank to remove the members by their ranks.Using the zremrangebyscore to remove
the members by their scores.Using the zremrangebylex to remove the members by their rank and lexicography.
zrem set- a
zrem set- b c
zremrangebyrank set-
zremrangebyscore set-
zremrangebylex set- (e (j
If we want to know a member's score,we can use zscore to get its score.To get the score of member e,
we use zscore set- e .For learning how many members in the set by the range of score,we can use zcount
to get the amount.To get the amount of the set by the score's range [0,10],we can use zcount set- .
Can we modify the scores of the members?Of course we can.Not only the exists member but also the
member not in the set.If the member not exists in the set,Redis will store a new member to the set.For
example,I want to modify the score of d which is not exists in the set.I will use zincrby set- d to finish
this easy job.And the result is that the set will has a new member with score 1.
OK,thoes commands are what I want to show you for sorted set.Let's go on to see how StackExchange.Redis
Handle the sorted set.
//zadd
db.SortedSetAdd("set-1", "a", );
var set_1 = new SortedSetEntry[]
{
new SortedSetEntry("b",),
new SortedSetEntry("c",),
new SortedSetEntry("d",),
new SortedSetEntry("e",),
new SortedSetEntry("f",),
new SortedSetEntry("g",),
new SortedSetEntry("h",),
new SortedSetEntry("i",),
new SortedSetEntry("j",),
new SortedSetEntry("k",)
};
db.SortedSetAdd("set-1", set_1); //zrange
Console.WriteLine("rank by score ascending");
foreach (var item in db.SortedSetRangeByRank("set-1", , -, Order.Ascending))
{
Console.Write(item + " ");
}
Console.WriteLine("");
foreach (var item in db.SortedSetRangeByRankWithScores("set-1"))
{
Console.WriteLine(string.Format("the {0} with score {1}", item.Element, item.Score));
}
//zrangebyscore
Console.WriteLine("sorted by score");
foreach (var item in db.SortedSetRangeByScore("set-1",,))
{
Console.Write(item + " ");
}
Console.WriteLine("");
//zrangebylex
Console.WriteLine("sorted by value");
foreach (var item in db.SortedSetRangeByValue("set-1","a","z"))
{
Console.Write(item + " ");
}
Console.WriteLine("");
//zrank
Console.WriteLine(string.Format("d rank in {0} by ascending", db.SortedSetRank("set-1", "d", Order.Ascending)));
Console.WriteLine(string.Format("d rank in {0} by descending", db.SortedSetRank("set-1", "d", Order.Descending))); //zrem
db.SortedSetRemove("set-1", "a");
db.SortedSetRemove("set-1", new RedisValue[] { "b", "c" });
Console.WriteLine("after removing - 1:");
foreach (var item in db.SortedSetRangeByRank("set-1", , -, Order.Ascending))
{
Console.Write(item + " ");
} //zrembyrangebyrank
db.SortedSetRemoveRangeByRank("set-1", , );
Console.WriteLine("\nafter removing by rank:");
foreach (var item in db.SortedSetRangeByRank("set-1", , -, Order.Ascending))
{
Console.Write(item + " ");
}
//zremrangeby score
db.SortedSetRemoveRangeByScore("set-1", , );
Console.WriteLine("\nafter removing by score:");
foreach (var item in db.SortedSetRangeByRank("set-1", , -, Order.Ascending))
{
Console.Write(item + " ");
}
//zremrangebylex
db.SortedSetRemoveRangeByValue("set-1", "d", "g");
Console.WriteLine("\nafter removing by value:");
foreach (var item in db.SortedSetRangeByRank("set-1", , -, Order.Ascending))
{
Console.Write(item + " ");
}
Console.WriteLine("");
//zscore
Console.WriteLine(string.Format("the score of e is {0}", db.SortedSetScore("set-1", "e")));
//zcount
Console.WriteLine(string.Format("{0} members in set-1", db.SortedSetLength("set-1")));
//zincrby
Console.WriteLine(string.Format("the score of d increase by 1 is {0}", db.SortedSetIncrement("set-1", "d", )));
When you debug the above code,the results are as follow.
The next post of this series is the basic opreation of List in Redis.Thanks for your reading.
