如何在 .NET 程式中使用 Redis 做為 Cache Server - Part 4 (使用 Sets 型別)

今天來看看 Sets 該怎麼使用，建議可與如何在 .NET 程式中使用 Redis 做為 Cache Server - Part 3 (使用 Lists 型別) 參照

先說重點：用法與 Lists 幾乎相同，差別是 Sets 的元素不允許重複，如果有興趣多瞭解 StackExchange.Redis 指令對應文中有對應與簡介說明表

基礎建設

處理 redis 連線 factory

使用 StackExchange.Redis 套件，記得 nuget 安裝

public static class RedisConnectionFactory
{
    private static readonly Lazy<ConnectionMultiplexer> Connection;
    static RedisConnectionFactory()
    {
        var connectionString = "localhost:6379";
        var options = ConfigurationOptions.Parse(connectionString);
        Connection = new Lazy<ConnectionMultiplexer>(() => ConnectionMultiplexer.Connect(options));
    }
    public static ConnectionMultiplexer GetConnection => Connection.Value;
    public static IDatabase RedisDB => GetConnection.GetDatabase();
}

測試用自訂 class

public class Person
{
    public string ID{ get; set; }
        
    public string Name { get; set; }
    
    public string Tel { get; set; }
}

存取 redis 用的 object

IDatabase _db = RedisConnectionFactory.RedisDB;

製造假資料

Dictionary<string, List<Person>> peopleDic = new Dictionary<string, List<Person>>();
for (int i = 0; i < 3; i++)
{
    var _id = Guid.NewGuid().ToString();
    List<Person> people = new List<UserQuery.Person>();
    for (int j = 0; j < 3; j++)
    {
        people.Add((new Person { ID = $"{i}_{j}_ID", Name = $"{i}_{j}_yowko", Tel = $"{i}_{j}_0123456789" }));
    }
    peopleDic.Add(_id, people);
}

使用 batch 來批次處理指令
```
var batch = _db.CreateBatch();
```

使用 Sets 型別

相關指令介紹

指令	參數	對應 StackExchange.Redis 指令	說明
SADD	key member [member …]	SetAdd/SetAddAsync	添加一個或者多個元素(member) 到 set(key) 裡
SCARD	key	SetLength/SetLengthAsync	取得 set(key) 裡面的元素數量
SDIFF	key [key …]	SetCombine/SetCombineAsync	取得一個 set(key) 與其他 set(key) 間的差集元素
SDIFFSTORE	destination key [key …]	SetCombineAndStore/SetCombineAndStoreAsync	將一個 set(key) 與其他 set 間的差集元素，儲存至 destination
SINTER	key [key …]	SetCombine/SetCombineAsync	取得兩個 set 的交集
SINTERSTORE	destination key [key …]	SetCombineAndStore/SetCombineAndStoreAsync	將一個 set(key) 與其他 set 間的交集，儲存至 destination
SISMEMBER	key member	SetContains/SetContainsAsync	檢查 member 存在於特定 set(key)
SMEMBERS	key	SetMembers/SetMembersAsync	取得 set(key) 裡面的所有元素
SMOVE	source destination member	SetMove/SetMoveAsync	移動 set(source) 裡面的元素(member) 到另一個 set(destination)
SPOP	key [count]	SetPop/SetPopAsync	刪除並取得 set(key) 裡的 count 個元素
SRANDMEMBER	key [count]	SetRandomMember/SetRandomMemberAsync SetRandomMembers/SetRandomMembersAsync	從 set(key) 裡面隨機獲取 count 個元素
SREM	key member [member …]	SetRemove/SetRemoveAsync	從 set(key) 裡刪除一個或多個元素(member)
SUNION	key [key …]	SetCombine/SetCombineAsync	傳回多個 set(key) 的聯集的所有元素(member)
SUNIONSTORE	destination key [key …]	SetCombineAndStore/SetCombineAndStoreAsync	將多個 set(key) 的聯集的所有元素，儲存至 destination
SSCAN	key cursor [MATCH pattern] [COUNT count]	SetScan	逐一列出 set(key) 中的元素

實際使用

範例程式碼

var batch = _db.CreateBatch();
foreach (var item in peopleDic)
{
    foreach (var element in item.Value)
    {
        _db.SetAddAsync(item.Key, JsonConvert.SerializeObject(element));
    }
}
batch.Execute();

儲存狀況

完整程式碼

void Main()
{
    IDatabase _db = RedisConnectionFactory.RedisDB;
    Dictionary<string, List<Person>> peopleDic = new Dictionary<string, List<Person>>();
    for (int i = 0; i < 3; i++)
    {
        var _id = Guid.NewGuid().ToString();
        List<Person> people = new List<UserQuery.Person>();
        for (int j = 0; j < 3; j++)
        {
            people.Add((new Person { ID = $"{i}_{j}_ID", Name = $"{i}_{j}_yowko", Tel = $"{i}_{j}_0123456789" }));
        }
        peopleDic.Add(_id, people);
    }
    var batch = _db.CreateBatch();
    foreach (var item in peopleDic)
    {
        foreach (var element in item.Value)
        {
            _db.SetAddAsync(item.Key, JsonConvert.SerializeObject(element));
        }
    }
    batch.Execute();
}

public class Person 
{
    public string ID { get; set; }

    public string Name { get; set; }

    public string Tel { get; set; }
}

public static class RedisConnectionFactory
{
    private static readonly Lazy<ConnectionMultiplexer> Connection;
    static RedisConnectionFactory()
    {
        var connectionString = "localhost:6379";
        var options = ConfigurationOptions.Parse(connectionString);
        Connection = new Lazy<ConnectionMultiplexer>(() => ConnectionMultiplexer.Connect(options));
    }
    public static ConnectionMultiplexer GetConnection => Connection.Value;
    public static IDatabase RedisDB => GetConnection.GetDatabase();
}

文章目錄

如何在 .NET 程式中使用 Redis 做為 Cache Server - Part 4 (使用 Sets 型別)

基礎建設

使用 Sets 型別

實際使用

完整程式碼

參考資料