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。

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 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 3 −它将显示确认消息。现在点击“是”按钮。

您将看到仪表板上不再有 TempCollection1。

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。

Step 1 −让我们通过指定要删除的集合的 ID 来删除该集合。

这是按 ID 查询以获取删除资源所需的 selfLinks 的常用模式。

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。

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。

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

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。

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。

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