Documentdb 简明教程

DocumentDB - Delete Collection

要删除集合或集合，您可以使用 .Net SDK 从门户和代码中执行此操作。

To drop collection or collections you can do the same from the portal as well as from the code by using .Net SDK.

Step 1 −转到 Azure 门户上的 DocumentDB 帐户。为了演示的目的，我添加了另外两个集合，如以下屏幕截图所示。

Step 1 − Go to your DocumentDB account on Azure portal. For the purpose of demo, I have added two more collections as seen in the following screenshot.

Step 2 −要删除任何集合，您需要单击该集合。选择 TempCollection1。您将看到以下页面，选择“删除集合”选项。

Step 2 − To drop any collection, you need to click on that collection. Let’s select TempCollection1. You will see the following page, select the ‘Delete Collection’ option.

Step 3 −它将显示确认消息。现在点击“是”按钮。

Step 3 − It will display the confirmation message. Now click ‘Yes’ button.

您将看到仪表板上不再有 TempCollection1。

You will see that the TempCollection1 is no more available on your dashboard.

您还可以使用 .Net SDK 从代码中删除集合。为此，请执行以下步骤。

You can also delete collections from your code using .Net SDK. To do that, following are the following steps.

Step 1 −让我们通过指定要删除的集合的 ID 来删除该集合。

Step 1 − Let’s delete the collection by specifying the ID of the collection we want to delete.

这是按 ID 查询以获取删除资源所需的 selfLinks 的常用模式。

It’s the usual pattern of querying by Id to obtain the selfLinks needed to delete a resource.

private async static Task DeleteCollection(DocumentClient client, string collectionId) {
   Console.WriteLine();
   Console.WriteLine("**** Delete Collection {0} in {1} ****", collectionId, database.Id);

   var query = new SqlQuerySpec {
      QueryText = "SELECT * FROM c WHERE c.id = @id",
         Parameters = new SqlParameterCollection {
         new SqlParameter {
            Name = "@id", Value = collectionId
         }
      }
   };

   DocumentCollection collection = client.CreateDocumentCollectionQuery(database.SelfLink,
      query).AsEnumerable().First();

   await client.DeleteDocumentCollectionAsync(collection.SelfLink);
   Console.WriteLine("Deleted collection {0} from database {1}", collectionId,
      database.Id);
}

在这里，我们将看到构造参数化查询的首选方式。我们没有对 collectionId 进行硬编码，因此此方法可用于删除任何集合。我们通过 Id 查询特定集合，其中 Id 参数在此 SqlParameterCollection 中定义，该 SqlParameterCollection 已分配给该 SqlQuerySpec 的参数属性。

Here we see the preferred way of constructing a parameterized query. We’re not hardcoding the collectionId so this method can be used to delete any collection. We are querying for a specific collection by Id where the Id parameter is defined in this SqlParameterCollection assigned to the parameter’s property of this SqlQuerySpec.

然后，SDK 会继续构建最终的查询字符串，以便 DocumentDB 将 collectionId 嵌入在其中。

Then the SDK does the work of constructing the final query string for DocumentDB with the collectionId embedded inside of it.

Step 2 −运行查询，然后使用其 SelfLink 从 CreateDocumentClient 任务中删除该集合。

Step 2 − Run the query and then use its SelfLink to delete the collection from the CreateDocumentClient task.

private static async Task CreateDocumentClient() {
   // Create a new instance of the DocumentClient

   using (var client = new DocumentClient(new Uri(EndpointUrl), AuthorizationKey)) {
      database = client.CreateDatabaseQuery("SELECT * FROM c WHERE c.id =
         'myfirstdb'").AsEnumerable().First();
      await DeleteCollection(client, "TempCollection");
   }
}

以下是 Program.cs 文件的完整实现。

Following is the complete implementation of Program.cs file.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Microsoft.Azure.Documents;
using Microsoft.Azure.Documents.Client;
using Microsoft.Azure.Documents.Linq;

using Newtonsoft.Json;

namespace DocumentDBDemo {

   class Program {

      private const string EndpointUrl = "https://azuredocdbdemo.documents.azure.com:443/";

      private const string AuthorizationKey = "BBhjI0gxdVPdDbS4diTjdloJq7Fp4L5RO/
         StTt6UtEufDM78qM2CtBZWbyVwFPSJIm8AcfDu2O+AfV T+TYUnBQ==";

      private static Database database;

      static void Main(string[] args) {
         try {
            CreateDocumentClient().Wait();
         } catch (Exception e) {
            Exception baseException = e.GetBaseException();
            Console.WriteLine("Error: {0}, Message: {1}", e.Message, baseException.Message);
         }
         Console.ReadKey();
      }

      private static async Task CreateDocumentClient() {
         // Create a new instance of the DocumentClient
         using (var client = new DocumentClient(new Uri(EndpointUrl), AuthorizationKey)) {
            database = client.CreateDatabaseQuery("SELECT * FROM c WHERE c.id =
               'myfirstdb'").AsEnumerable().First();
            await DeleteCollection(client, "TempCollection");

            //await CreateCollection(client, "MyCollection1");
            //await CreateCollection(client, "MyCollection2", "S2");
            ////await CreateDatabase(client);
            //GetDatabases(client);
            //await DeleteDatabase(client);
            //GetDatabases(client);
         }
      }

      private async static Task CreateCollection(DocumentClient client,
         string collectionId, string offerType = "S1") {

         Console.WriteLine();
         Console.WriteLine("**** Create Collection {0} in {1} ****", collectionId,
            database.Id);

         var collectionDefinition = new DocumentCollection { Id = collectionId };
         var options = new RequestOptions { OfferType = offerType };
         var result = await client.CreateDocumentCollectionAsync(database.SelfLink,
            collectionDefinition, options);

         var collection = result.Resource;

         Console.WriteLine("Created new collection");
         ViewCollection(collection);
      }

      private static void ViewCollection(DocumentCollection collection) {
         Console.WriteLine("Collection ID: {0} ", collection.Id);
         Console.WriteLine("Resource ID: {0} ", collection.ResourceId);
         Console.WriteLine("Self Link: {0} ", collection.SelfLink);
         Console.WriteLine("Documents Link: {0} ", collection.DocumentsLink);
         Console.WriteLine("UDFs Link: {0} ", collection.UserDefinedFunctionsLink);
         Console.WriteLine("StoredProcs Link: {0} ", collection.StoredProceduresLink);
         Console.WriteLine("Triggers Link: {0} ", collection.TriggersLink);
         Console.WriteLine("Timestamp: {0} ", collection.Timestamp);
      }

      private async static Task DeleteCollection(DocumentClient client,
         string collectionId) {

         Console.WriteLine();
         Console.WriteLine("**** Delete Collection {0} in {1} ****", collectionId,
            database.Id);

         var query = new SqlQuerySpec {
            QueryText = "SELECT * FROM c WHERE c.id = @id", Parameters = new
               SqlParameterCollection {
               new SqlParameter {
                  Name = "@id", Value = collectionId
               }
            }
         };

         DocumentCollection collection = client.CreateDocumentCollectionQuery
            (database.SelfLink, query).AsEnumerable().First();

         await client.DeleteDocumentCollectionAsync(collection.SelfLink);
         Console.WriteLine("Deleted collection {0} from database {1}", collectionId,
            database.Id);
      }

   }
}

当上文代码被编译和执行时，您将收到如下输出。

When the above code is compiled and executed, you will receive the following output.

**** Delete Collection TempCollection in myfirstdb ****
Deleted collection TempCollection from database myfirstdb