Question

我必须将一个项目插入集合中。我必须对GetProvider使用的代码可以使用Microsoft.Azure.Documents.Client类。我在Microsoft网站上找到了一些示例代码来进行插入。它需要使用Microsoft.Azure.Cosmos类。该代码有一个错误，容器未定义。因此，我添加了Container容器，并清除了该错误，但是由于没有初始化程序，因此现在可以使用未初始化的对象错误。我的应用程序是.NET Core 3.0 WEB API。

下面的代码是我实现插入的方式。有没有办法只使用Microsoft.Azure.Cosmos库进行插入？

using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using SchedulingAppointmentAPI.Models;
using System;
using System.Linq;
using System.Threading.Tasks;
using System.Net;
using Microsoft.Azure.Cosmos;
using Microsoft.Azure.Documents.Client;
using Microsoft.Azure.Documents;
using ConnectionMode = Microsoft.Azure.Documents.Client.ConnectionMode;
using Database = Microsoft.Azure.Documents.Database;
using PartitionKey = Microsoft.Azure.Cosmos.PartitionKey;

public async void SaveAppointment(Appointments appointment)
        {
            try
            {
                using (client = new DocumentClient(new Uri(EndpointUrl), AuthorizationKey,
                      new ConnectionPolicy { ConnectionMode = ConnectionMode.Gateway, ConnectionProtocol = Protocol.Https }))
                {
                    Database databasename = await client.CreateDatabaseIfNotExistsAsync(new Database { Id = DatabaseName });
                    DocumentCollection collectionname = await GetOrCreateCollectionAsync(DatabaseName, CollectionName);
                    Container container;// = await Database.CreateContainerAsync("container-id");
                    Uri collectionUri = UriFactory.CreateDocumentCollectionUri(DatabaseName, CollectionName);

                    try
                    {
                        // Read the item to see if it exists.  
                        ItemResponse<Appointments> appointmentItemResponse = await container.ReadItemAsync<Appointments>(appointment.id.ToString(), new PartitionKey(appointment.Provider_Id));
                    }

                    catch (CosmosException ex) when (ex.StatusCode == HttpStatusCode.NotFound)
                    {
                        // Create an item in the container representing the appointment. Note we provide the value of the partition key for this item, which is "ProviderID"
                        ItemResponse<Appointments> appointmentItemResponse = await container.CreateItemAsync<Appointments>(appointment, new PartitionKey(appointment.Provider_Id));

                    }

Answer 1

正如@David所正确指出的那样，由于容器未初始化，您将得到null引用错误，您可以使用类似以下的内容：

我们在Cosmos DB中需要一个数据库和几个集合。

var client = new CosmosClient(Endpoint, Authkey);
await client.Databases.CreateDatabaseIfNotExistsAsync("DatabaseId", 400);
await client.Databases["DatabaseId"].Containers.CreateContainerIfNotExistsAsync("ContainerA", "/partitionKey");
await client.Databases["DatabaseId"].Containers.CreateContainerIfNotExistsAsync("ContainerB", "/partitionKey");

要获取现有数据库/集合上的元数据，我们可以这样做：

await client.Databases["DatabaseId"].ReadAsync();
await client.Databases["DatabaseId"].Containers["ContainerA"].ReadAsync();

要创建实体，我们需要：

var item = new SampleEntity
{
    Id= Guid.NewGuid().ToString(),
    Name = "Sample",
    PartitionKey = "a"
};
CosmosItemResponse<SampleEntity> res = await container.Items.CreateItemAsync(item.PartitionKey, item);

您可以参考以下存储库来管理容器：

https://github.com/Azure/azure-cosmos-dotnet-v3/blob/master/Microsoft.Azure.Cosmos.Samples/Usage/ContainerManagement/Program.cs

其他参考：

https://joonasw.net/view/exploring-cosmos-db-sdk-v3

希望有帮助。

需要帮助将物品插入Cosmos Collection

1 个答案: