c# - 使用 ServiceStack.Redis C# .Net 在 Redis 服务器中从第 m 行到第 n 行搜索数据

Question

我的 Redis 服务器在数据键 [urn:Customer] 中有 1000 行客户行。我需要从该记录集中获取分页结果以用于我的自动完成过程。

我的代码:

var custDetails = from C in nwDB.Customers
                  select new { 
                      C.CustomerID, C.CompanyName, 
                      C.ContactName, C.City, 
                      C.Country, C.PostalCode, 
                      C.Phone, C.Fax 
                  };

using (var redis = new RedisClient())
{
    redis.FlushDb();
    redis.FlushAll();

    var RedisUsers = redis.As<CustomerR>();
    RedisUsers.SetSequence(0);

    foreach (var eachCustomer in custDetails)
    {
        RedisUsers.Store(new CustomerR
        {
            RedisCustID = RedisUsers.GetNextSequence(),
            CustomerID = eachCustomer.CustomerID,
            CompanyName = eachCustomer.CompanyName,
            ContactName = eachCustomer.ContactName,
            City = eachCustomer.City,
            Country = eachCustomer.PostalCode,
            Phone = eachCustomer.Phone,
            Fax = eachCustomer.Fax
        });
    }

    var allThepeople = RedisUsers.GetAll();
    gvCustomers.DataSource = allThepeople;
    gvCustomers.DataBind();
}

我需要使用 RedisUsers.GetNextSequence() 值仅显示前 50 行，而不是 GetAll()。

Answer 1

为每个客户使用一个 key

最好将每个客户存储为他们自己的 key 。 即 urn:Customer:123将代表 CustomerID = 123。

这为我们提供了一个优势，即只需选择该键即可通过客户的 ID 访问客户。但它也让我们能够SCAN与客户 key 模式匹配的 key 。即 urn:Customer:<id> .

您还可以避免创建任意 RedisCustID , 只需使用 CustomerID , 它将避免很多困惑。

存储客户:

var custDetails = from c in nwDB.Customers select new { 
    c.CustomerID, 
    c.CompanyName, 
    c.ContactName, 
    c.City, 
    c.Country, 
    c.PostalCode, 
    c.Phone, 
    c.Fax
};

using (var redis = new RedisClient())
{
    var customers = redis.As<CustomerR>();

    foreach(var customer in custDetails)
    {
        // The key for this customer
        var customerKey = string.Format("Customer:{0}", customer.CustomerID);

        // Store the customer
        // Use ConvertTo<T> to auto map the properties
        customers.SetEntry(customerKey, customer.ConvertTo<CustomerR>());
    }
}

通过 Id 检索客户:

using (var redis = new RedisClient())
{
    var customers = redisClient.As<CustomerR>();
    var customerKey = string.Format("Customer:{0}", 123);
    var customer = customers.GetValue(customerKey);
}

检索所有客户:

using (var redis = new RedisClient())
{
    var customerKeys = redis.ScanAllKeys("Customer:*").ToList();
    var allCustomers = redis.GetValues<CustomerR>(customerKeys);
}

检索前 50 个客户:

ScanAllKeys方法允许您对结果进行分页，这正是您最终想要做的。

using (var redis = new RedisClient())
{
    var customerKeys = redis.ScanAllKeys("Customer:*", 50).ToList();
    var top50Customers = redis.GetValues<CustomerR>(customerKeys);
}

检索特定范围内的客户:

即获取尺寸为 10 的第 3 页

int page = 3;
int pageSize = 10;

int startAt = pageSize * page;
int endAt = startAt + pageSize;

using (var redis = new RedisClient())
{
    var pagedCustomerKeys = redis.ScanAllKeys("Customer:*", endAt).ToList().Skip(startAt).Take(pageSize);
    var pagedCustomers = redis.GetValues<CustomerR>(pagedCustomerKeys);
}

如果您想了解如何更新客户或删除客户 see this answer ，其中提供了更多示例。

希望对您有所帮助。