使用 gremlin 查询将 Orient Vertex 迁移到 Cosmos DB

Question

所以我有一个 orient 2.0.0 db，我想将这个 db 移动到 cosmos db。我使用的技术是.Net，所以我不能使用java，还有其他更丰富的驱动。

我在迁移过程中面临的主要问题是我的东方顶点包含作为对象的属性。那么有没有一种方法可以使用 gremlin 查询将对象添加为属性到 cosmos db.

tinkerpop doc, and Azure Cosmos DB Docs for gremlin 上的示例都显示仅添加简单数据类型。

Answer 1

据我所知，目前不支持使用 gremlin 查询向 cosmos 数据库添加对象属性。

我的解决方法是我们可以将对象弄平。我写了一个测试demo，你可以添加你自己的逻辑。

以下是我的详细步骤：

1.Create一个C#项目并添加Microsoft.Azure.Graphs SDK，更多细节请参考packages.config部分。

2.Add 自定义 class 项目

public class Custom
    {
        public string Type { get; set; }
        public string Name { get; set; }
    }

3。添加一个函数来将对象隐藏到 Gremlin 字符串

 public static string CovertToGremlinString(object pObject,string type)
        {
            var propertyList = new List<string>();
           // var dic = new Dictionary<string, string>();
            if (pObject == null) return null;
            var jobject = JObject.FromObject(pObject);
            propertyList.AddRange(pObject.GetType().GetProperties().Select(prop => prop.Name));
            var s = propertyList.Aggregate($"g.addV('{type}')", (current, property) => current + $".property('{property}','{jobject[property]})')");
           // dic.Add(type, s);
            return s;
        }

4.Add RunAsync 函数，我们也可以从 Azure 门户获取演示代码

public async Task RunAsync(DocumentClient client)
    {
        Database database = await client.CreateDatabaseIfNotExistsAsync(new Database { Id = "graphdb" });

        DocumentCollection graph = await client.CreateDocumentCollectionIfNotExistsAsync(
            UriFactory.CreateDatabaseUri("graphdb"),
            new DocumentCollection { Id = "Custom" },
            new RequestOptions { OfferThroughput = 1000 });

        // Azure Cosmos DB supports the Gremlin API for working with Graphs. Gremlin is a functional programming language composed of steps.
        // Here, we run a series of Gremlin queries to show how you can add vertices, edges, modify properties, perform queries and traversals
        // For additional details, see https://aka.ms/gremlin for the complete list of supported Gremlin operators
        var custom = new Custom
        {
            Name = "Tom",
            Type = "1"
        };
        var s = CovertToGremlinString(custom, "custom");
        Dictionary<string, string> gremlinQueries = new Dictionary<string, string>
        {
            {"Cleanup", "g.V().drop()"},
            {"AddVertex 1", s}
        };

        foreach (KeyValuePair<string, string> gremlinQuery in gremlinQueries)
        {
            Console.WriteLine($"Running {gremlinQuery.Key}: {gremlinQuery.Value}");


            // The CreateGremlinQuery method extensions allow you to execute Gremlin queries and iterate
            // results asychronously
            IDocumentQuery<dynamic> query = client.CreateGremlinQuery<dynamic>(graph, (string) gremlinQuery.Value);
            while (query.HasMoreResults)
            {
                foreach (dynamic result in await query.ExecuteNextAsync())
                {
                    Console.WriteLine($"\t {JsonConvert.SerializeObject(result)}");
                }
            }

            Console.WriteLine();
        }

5.Test 在本地。

    string endpoint = ConfigurationManager.AppSettings["Endpoint"];
    string authKey = ConfigurationManager.AppSettings["AuthKey"];

    using (DocumentClient client = new DocumentClient(
                new Uri(endpoint),
                authKey,
                new ConnectionPolicy { ConnectionMode = ConnectionMode.Direct, ConnectionProtocol = Protocol.Tcp }))
            {
                Program p = new Program();
                p.RunAsync(client).Wait();
            }

packages.config

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="Microsoft.Azure.DocumentDB" version="1.14.0" targetFramework="net452" />
  <package id="Microsoft.Azure.Graphs" version="0.2.0-preview" targetFramework="net452" />
  <package id="Microsoft.CodeAnalysis.Analyzers" version="1.1.0" targetFramework="net452" />
  <package id="Microsoft.CodeAnalysis.Common" version="1.3.0" targetFramework="net452" />
  <package id="Microsoft.CodeAnalysis.CSharp" version="1.3.0" targetFramework="net452" />
  <package id="Newtonsoft.Json" version="6.0.8" targetFramework="net452" />
  <package id="System.Collections" version="4.0.0" targetFramework="net452" />
  <package id="System.Collections.Immutable" version="1.1.37" targetFramework="net452" />
  <package id="System.Diagnostics.Debug" version="4.0.0" targetFramework="net452" />
  <package id="System.Globalization" version="4.0.0" targetFramework="net452" />
  <package id="System.Linq" version="4.0.0" targetFramework="net452" />
  <package id="System.Reflection.Metadata" version="1.2.0" targetFramework="net452" />
  <package id="System.Resources.ResourceManager" version="4.0.0" targetFramework="net452" />
  <package id="System.Runtime" version="4.0.0" targetFramework="net452" />
  <package id="System.Runtime.Extensions" version="4.0.0" targetFramework="net452" />
  <package id="System.Threading" version="4.0.0" targetFramework="net452" />
</packages>

使用 gremlin 查询将 Orient Vertex 迁移到 Cosmos DB

Migrating Orient Vertex to Cosmos DB using gremlin query

gremlin

tinkerpop3

azure-cosmosdb