如何:用c#和elasticsearch.net为elasticsearch索引子节点

我有以下映射为我的elasticsearch数据库:

{
    "mappings": {
        "customer": {
            "properties": {
                "name": {"type": "string"},
                "lastname": {"type": "string"},
                "age": {"type": "date"},
                "hometown": {"type": "string"},
                "street": {"type": "string"},
                "nr": {"type": "integer"}
          }
        },
        "purchase": {
            "_parent": {"type": "customer"},
            "properties": {
                "time": {"type": "long"},
                "productnr1": {"type": "integer"},
                "productnr2": {"type": "integer"},
                "productnr3": {"type": "integer"},
                "totalcost": {"type": "double"}
            }
        }
    }
}

现在我想索引我的孩子(购买)通过使用客户端(elasticsearch.net)在visual studio。我可以索引和升级我的父母(客户)没有问题。但我找不到索引子节点的方法。

我得到了以下不完整的工作代码:

using Newtonsoft.Json;
using Elasticsearch.Net;
namespace programname
{ 
    static class program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main()
        {
            Class_GetData Class_GetData = new Class_GetData();
            //connecting to elasticsearch (**this is working**)
            var node = new Uri("http://localhost:9200");
            var config = new Elasticsearch.Net.Connection.ConnectionConfiguration(node);
            var client = new ElasticsearchClient(config);
            //some variables
            string username =  Class_GetData.Getname();
            string userlastname = Class_GetData.Getlastname();
            string userhometown = Class_GetData.Gethometown();
            string userstreet = Class_GetData.Getstreet()
            string userage = Class_GetData.Getage()
            int userhomenr = Class_GetData.Getnr();
            int userpruductnr1 = Class_GetData.Getproductnr1();
            int userpruductnr2 = Class_GetData.Getproductnr2();  
            int userpruductnr3 = Class_GetData.Getproductnr3();             
            double usertotalcost = Class_GetData.Gettotalcost();    
            var today = DateTime.Today;             
            var date = today.Year + "-" + today.Month + "-" + today.Day;
            var id = username + "_" + userlastname + "_" + date;
            //check if parent exist (this is also working)
            ElasticsearchResponse<DynamicDictionary> response = client.Get("test", "customer", id);
            dynamic found;
            response.Response.TryGetValue("found", out found);
            if (!found.HasValue)
            {
                return;
            }
            if (!found.Value)
            {
                var customer = new
                {
                name = username,
                lastname = userlastname,
                age = userage,
                hometown = userhometown,
                street = userstreet,
                nr = userhomenr,
                };
                client.Index("test", "customer", id, customer);
            }
            //**maybe this is already false?**
            var purchaseproperties = new
            {
                time = DateTime.Now.Ticks,
                productnr1 = userpruductnr1,
                productnr2 = userpruductnr2,
                productnr3 = userpruductnr3,
                totalcost = usertotalcost,
            };
            //**this is the main problem... child wont create**
            client.Index("test/customer/", "purchase", purchaseproperties); 
            //working line:
            client.Index("test", "purchase", purchaseproperties, d => d.Parent(_parentId));

所以现在我希望这个代码是自我解释和有人可以帮助我。我真的试图使它最简单的方式，我尝试了很多其他不工作的索引行。我也希望有一个解决方案，索引一个孩子的父母不使用巢客户端为visual studio。

client.Index("test", "purchase", purchaseproperties, d => d.Parent(_parentId));