[DocumentDB .NET SDK]替换时 ReadDocumentAsync 和 CreateDocumentQ

Question

请先看代码。

在步骤 8 中，不会更新该字段。 在步骤11和12中，该字段已更新。

我有两个问题。

替换时，ReadDocumentAsync 和 CreateDocumentQuery 有什么区别？

是否适合使用 DocumentQuery 获取的值进行替换？

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控制台应用

NuGet Package(Microsoft.Azure.DocumentDB 1.19.1，Newtonsoft.Json 9.0.1)

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using Microsoft.Azure.Documents;
using Microsoft.Azure.Documents.Client;
using Microsoft.Azure.Documents.Linq;
using Newtonsoft.Json;
using System;
using System.Collections.ObjectModel;
using System.Configuration;
using System.Linq;
class Program
{
static string endpoint = ConfigurationManager.AppSettings["endpoint"];
static string key = ConfigurationManager.AppSettings["key"];
static string database = ConfigurationManager.AppSettings["database"];
static string collection = ConfigurationManager.AppSettings["collection"];
static void Main(string[] args)
{
ConnectionPolicy cp = new ConnectionPolicy()
{
ConnectionMode = ConnectionMode.Direct,
ConnectionProtocol = Protocol.Https,
RetryOptions = new RetryOptions()
{
MaxRetryAttemptsOnThrottledRequests = 5,
MaxRetryWaitTimeInSeconds = 60,
}
};
var client = new DocumentClient(new Uri(endpoint), key, cp);
//Step1 Create Database
client.CreateDatabaseIfNotExistsAsync(new Database { Id = database }).Wait();
//Step2 Create Collection(400RU)
client.CreateDocumentCollectionIfNotExistsAsync(UriFactory.CreateDatabaseUri(database),
new DocumentCollection
{
Id = collection,
PartitionKey = new PartitionKeyDefinition()
{ Paths = new Collection<string>() { "/partitionKey" } }
}
, new RequestOptions { OfferThroughput = 400 }).Wait();
//Step3 Insert TestData
var id1 = Guid.NewGuid().ToString();
client.CreateDocumentAsync(UriFactory.CreateDocumentCollectionUri(database, collection)
, new TestDocument() { TestField = "initialvalue", PartitionKey = "default", Id = id1, }).Wait();
var id2 = Guid.NewGuid().ToString();
client.CreateDocumentAsync(UriFactory.CreateDocumentCollectionUri(database, collection)
, new TestDocument() { TestField = "initialvalue", PartitionKey = "default", Id = id2, }).Wait();
//Step4 ID1 GetDocument(ReadDocument)
var readDocument = client.ReadDocumentAsync<TestDocument>(UriFactory.CreateDocumentUri(database, collection, id1),
new RequestOptions() { PartitionKey = new PartitionKey("default") }).Result.Document;
//Step5 ID2 GetDocument(DocumentQuery)
var queryDocument = client.CreateDocumentQuery<TestDocument>(UriFactory.CreateDocumentCollectionUri(database, collection),
new FeedOptions { MaxItemCount = 1, EnableCrossPartitionQuery = false, })
.Where(x => x.PartitionKey == "default" && x.Id == id2)
.AsDocumentQuery().ExecuteNextAsync<TestDocument>().Result.FirstOrDefault();
//Step6 ChangeValue
readDocument.TestField = "newvalue";
queryDocument.TestField = "newvalue";
//Step7 ID1 Replace
var updateResult1 = client.ReplaceDocumentAsync(UriFactory.CreateDocumentUri(database, collection, readDocument.Id), readDocument).Result;
//Step8 ID2 Replace
var updateResult2 = client.ReplaceDocumentAsync(UriFactory.CreateDocumentUri(database, collection, queryDocument.Id), queryDocument).Result;
//Step9 ID1 select
var id1Updated = client.ReadDocumentAsync<TestDocument>(UriFactory.CreateDocumentUri(database, collection, id1),
new RequestOptions() { PartitionKey = new PartitionKey("default") }).Result.Document;
//Step10 ID2 select
var id2Updated = client.ReadDocumentAsync<TestDocument>(UriFactory.CreateDocumentUri(database, collection, id2),
new RequestOptions() { PartitionKey = new PartitionKey("default") }).Result.Document;
Console.WriteLine(id1Updated.TestField); //newvalue
Console.WriteLine(id2Updated.TestField); //initialvalue
Console.ReadLine();
//Step11 ID2 SetPropertyValue
queryDocument.SetPropertyValue("testField", "newvalue2");
//Step12 ID2 Replace
var updateResultX = client.ReplaceDocumentAsync(UriFactory.CreateDocumentUri(database, collection, queryDocument.Id), queryDocument).Result;
//Step13 ID2 select
var id2UpdatedX = client.ReadDocumentAsync<TestDocument>(UriFactory.CreateDocumentUri(database, collection, id2),
new RequestOptions() { PartitionKey = new PartitionKey("default") }).Result.Document;
Console.WriteLine(id2UpdatedX.TestField); //newvalue2
Console.ReadLine();
}
}
public class TestDocument : Document
{
[JsonProperty("partitionKey")]
public string PartitionKey { get; set; }
[JsonProperty("testField")]
public string TestField { get; set; }
}

Answer 1

ReadDocumentAsync 和 替换时创建文档查询？

对于简单的 ID 查找，应使用ReadDocumentAsync而不是查询。

在服务器端，ReadDocumentAsync(REST API 上的 GET)在吞吐量 (RU) 和延迟方面更轻量级。没有SQL解析/编译/索引扫描，它只是一个直接查找。

ReadDocumentAsync在找不到此处提到的特定文档(在状态代码中返回 404)时，将抛出该 DocumentClientException。

若要绕过处理此异常，可以先使用CreateDocumentQuery()进行查询而不是直接读取。然后，您只需获得一个结果集。

是否适合将文档查询获取的值用于 更换？

是的，您可以使用 DocumentQuery 获取的文档执行替换操作。请参考下面的代码片段：

private async Task updateDoc()
{
string EndpointUri = "xxxxx";
string PrimaryKey = "xxxxx";
DocumentClient client;
client = new DocumentClient(new Uri(EndpointUri), PrimaryKey);
Document doc = client.CreateDocumentQuery<Document>(UriFactory.CreateDocumentCollectionUri("db", "coll"))
.Where(r => r.Id == "**")
.AsEnumerable()
.SingleOrDefault();
MyMode mode= (dynamic)doc;
mode.name = "updated value";
//replace document
Document updateddoc = await client.ReplaceDocumentAsync(doc.SelfLink, mode);

Console.WriteLine(updateddoc);
}
public class MyMode
{
public string id { get; set; }
public string name { get; set; }
}

希望对您有所帮助。