所有的人，我正在用NEST玩ElasticSearch 6.x，为了简单起见，我根据这里提供的NEST 6.x文档，用下面的POCO设置创建了映射。 https:/www.elastic.coguideenelasticsearchclientnet-apicurrentparent-child-relationships.html. 我的数据模型是一个简单的模型，有
顾客
订购
包装
订单项目
以下是C# POCO的设置
[ElasticsearchType(Name = "customer")]
public class Customer
{
[PropertyName("customerId")]
public int CustomerId { get; set; }
[PropertyName("firstName")]
[Text]
public string FirstName { get; set; }
[PropertyName("lastName")]
[Text]
public string LastName { get; set; }
[PropertyName("email")]
[Keyword]
public string Email { get; set; }
[PropertyName("customer_join_field")]
public JoinField CustomerJoinField { get; set; }
}
[ElasticsearchType(Name = "order")]
public class Order : Customer
{
[PropertyName("orderId")]
public int OrderId { get; set; }
[PropertyName("orderAmount")]
public decimal Amount { get; set; }
[Nested]
[PropertyName("packages")]
public List<Package> Packages { get; set; }
[Nested]
[PropertyName("orderItems")]
public List<OrderItem> OrderItems { get; set; }
}
public class Package
{
public int PackageId { get; set; }
public int Qty { get; set; }
public int OrderId { get; set; }
public string Weight { get; set; }
}
public class OrderItem
{
public int OrderItemId { get; set; }
public int Quantity { get; set; }
public decimal UnitPrice { get; set; }
}
建立ES客户端
public static ElasticClient ESClient
{
get
{
var connectionPool = new SingleNodeConnectionPool(new Uri("http://localhost:9200"));
var settings = new ConnectionSettings(connectionPool)
.DefaultMappingFor<Customer>(i => i
.IndexName("fa")
.TypeName("customer"))
.DefaultMappingFor<Order>(i => i
.IndexName("fa")
.TypeName("customer"))
.EnableDebugMode()
.PrettyJson()
.RequestTimeout(TimeSpan.FromMinutes(2));
return new ElasticClient(settings);
}
}
配置索引(fa)
public static void ConfigureIndex()
{
try
{
var createIndexResponse = ESClient.CreateIndex("fa", c => c
.Index<Customer>()
.Mappings(ms => ms
.Map<Customer>(m => m
.RoutingField(r => r.Required())
.AutoMap<Customer>()
.AutoMap<Order>()
.Properties(props => props
.Join(j => j
.Name(p => p.CustomerJoinField)
.Relations(r => r
.Join<Customer, Order>()
)
)
)
)
)
);
}
添加客户和订单类型（在同一客户类型下，因为在ES 6.x中，一个索引只能有一个类型。
public static void AddCustomerDocument(Customer cust)
{
try
{
var result = ESClient.Index<Customer>(cust,
c => c
.Id(cust.CustomerId)//to avaoid random Ids
.Routing(cust.CustomerId)
);
//var response = ESClient.Index(cust, i => i.Routing(Routing.From(cust)));
}
catch (Exception ex)
{
throw;
}
}
public static void AddOrderDocument(Order order)
{
try
{
var result = ESClient.Index<Customer>(order,
c => c
.Id(order.OrderId)//to avaoid random Ids
.Routing(order.CustomerId)
);
//var response = ESClient.IndexDocument<Order>(order);
}
catch (Exception ex)
{
throw;
}
}
在ES中生成的映射是
{
"fa": {
"mappings": {
"customer": {
"_routing": {
"required": true
},
"properties": {
"customerId": {
"type": "integer"
},
"customer_join_field": {
"type": "join",
"eager_global_ordinals": true,
"relations": {
"customer": "order"
}
},
"email": {
"type": "keyword"
},
"firstName": {
"type": "text"
},
"lastName": {
"type": "text"
},
"orderAmount": {
"type": "double"
},
"orderId": {
"type": "integer"
},
"orderItems": {
"type": "nested",
"properties": {
"orderItemId": {
"type": "integer"
},
"quantity": {
"type": "integer"
},
"unitPrice": {
"type": "double"
}
}
},
"packages": {
"type": "nested",
"properties": {
"orderId": {
"type": "integer"
},
"packageId": {
"type": "integer"
},
"qty": {
"type": "integer"
},
"weight": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
}
}
}
}
}
}
}
}
我正在查询这个索引，以获得特定客户(CustomerId= 1)下的特定订单项目，单价为12.23。
这是我的查询DSL
{
"query":{
"parent_id":{
"type":"order",
"id":"1"
},
"nested":{
"path":"orderItems",
"score_mode":"avg",
"query":{
"bool":{
"must":[
{"match":{"orderItems.unitPrice" : "12.23"}}
]
}
}
}
}
}
当我这样做的时候，我得到以下错误信息
{
"error": {
"root_cause": [
{
"type": "parsing_exception",
"reason": "[parent_id] malformed query, expected [END_OBJECT] but found [FIELD_NAME]",
"line": 9,
"col": 4
}
],
"type": "parsing_exception",
"reason": "[parent_id] malformed query, expected [END_OBJECT] but found [FIELD_NAME]",
"line": 9,
"col": 4
},
"status": 400
}
我的问题是
在ES 6.x中，是否可以(或推荐)同时做父子关系和嵌套类型？
如果不可以，我的选择是否仅限于对模型进行去规范化处理（将Package、OrderItems作为Customer的子代，而不是Order，并在Package和OrderItems中添加字段？)还是对ES进行多次查询，并将我想要的数据格式扁平化的逻辑移到应用端？
这是我创建的示例数据( localhost:9200facustomer_search)
{
"took": 1,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"skipped": 0,
"failed": 0
},
"hits": {
"total": 3,
"max_score": 1,
"hits": [
{
"_index": "fa",
"_type": "customer",
"_id": "1",
"_score": 1,
"_routing": "1",
"_source": {
"customerId": 1,
"firstName": "Rennish",
"lastName": "Joseph",
"email": "[email protected]",
"customer_join_field": "customer"
}
},
{
"_index": "fa",
"_type": "customer",
"_id": "100",
"_score": 1,
"_routing": "1",
"_source": {
"orderId": 100,
"orderAmount": 23.45,
"packages": [
{
"packageId": 1,
"qty": 2,
"orderId": 1,
"weight": "2.3"
},
{
"packageId": 2,
"qty": 1,
"orderId": 1,
"weight": "2.5"
}
],
"orderItems": [
{
"orderItemId": 1,
"quantity": 2,
"unitPrice": 12.23
},
{
"orderItemId": 2,
"quantity": 1,
"unitPrice": 10.23
}
],
"customerId": 1,
"customer_join_field": {
"name": "order",
"parent": "1"
}
}
},
{
"_index": "fa",
"_type": "customer",
"_id": "101",
"_score": 1,
"_routing": "1",
"_source": {
"orderId": 101,
"orderAmount": 23.45,
"packages": [
{
"packageId": 1,
"qty": 2,
"orderId": 1,
"weight": "2.3"
},
{
"packageId": 2,
"qty": 1,
"orderId": 1,
"weight": "2.5"
}
],
"orderItems": [
{
"orderItemId": 1,
"quantity": 2,
"unitPrice": 12.23
},
{
"orderItemId": 2,
"quantity": 1,
"unitPrice": 10.23
}
],
"customerId": 1,
"customer_join_field": {
"name": "order",
"parent": "1"
}
}
}
]
}
}
我们最终为每个实体（Customer、Order、Package等）创建了单独的索引，并从我们的应用程序中针对所有这些索引进行查询，然后将结果合并到应用程序中。这是我们与Elasticsearch的顾问的建议。我们没有在任何一个索引映射中做父子关系。这也许对将来的人有帮助。