我对弹性搜索很新，并且一直试图让这种排序工作。一般的想法是使用嵌套消息和嵌套参与者搜索电子邮件消息线程。目标是在线程级别显示搜索结果，由正在进行搜索的参与者进行排序，并根据他们所在的邮箱对last_received_at或last_sent_at列进行排序。
我的理解是，你不能按照许多嵌套孩子中的单个孩子的价值进行排序。因此，为了做到这一点，我看到了一些关于将custom_score与脚本一起使用，然后对分数进行排序的建议。我的计划是动态更改排序列，然后运行嵌套的custom_score查询，该查询将返回其中一个参与者的日期作为分数。我一直注意到一些问题，得分格式都很奇怪（例如，最后总是有4个零），而且可能没有返回我期待的日期。
以下是索引的简化版本和相关查询。如果有人有任何建议，我将非常感激。 （仅供参考 - 我使用的是elasticsearch版本0.20.6。）
指数：
mappings: {
message_thread: {
properties: {
id: {
type: long
}
subject: {
dynamic: true
properties: {
id: {
type: long
}
name: {
type: string
}
}
}
participants: {
dynamic: true
properties: {
id: {
type: long
}
name: {
type: string
}
last_sent_at: {
format: dateOptionalTime
type: date
}
last_received_at: {
format: dateOptionalTime
type: date
}
}
}
messages: {
dynamic: true
properties: {
sender: {
dynamic: true
properties: {
id: {
type: long
}
}
}
id: {
type: long
}
body: {
type: string
}
created_at: {
format: dateOptionalTime
type: date
}
recipient: {
dynamic: true
properties: {
id: {
type: long
}
}
}
}
}
version: {
type: long
}
}
}
}
查询：
{
"query": {
"bool": {
"must": [
{
"term": { "participants.id": 3785 }
},
{
"custom_score": {
"query": {
"filtered": {
"query": { "match_all": {} },
"filter": {
"term": { "participants.id": 3785 }
}
}
},
"params": { "sort_column": "participants.last_received_at" },
"script": "doc[sort_column].value"
}
}
]
}
},
"filter": {
"bool": {
"must": [
{
"term": { "messages.recipient.id": 3785 }
}
]
}
},
"sort": [ "_score" ]
}
解决方案：
感谢@imotov，这是最终结果。参与者没有正确嵌套在索引中（而消息不需要）。此外，include_in_root用于参与者简化查询（参与者是小记录而不是真正的大小问题，尽管@imotov也提供了一个没有它的例子）。然后他重新构建了JSON请求以使用dis_max查询。
curl -XDELETE "localhost:9200/test-idx"
curl -XPUT "localhost:9200/test-idx" -d '{
"mappings": {
"message_thread": {
"properties": {
"id": {
"type": "long"
},
"messages": {
"properties": {
"body": {
"type": "string",
"analyzer": "standard"
},
"created_at": {
"type": "date",
"format": "yyyy-MM-dd'\''T'\''HH:mm:ss'\''Z'\''"
},
"id": {
"type": "long"
},
"recipient": {
"dynamic": "true",
"properties": {
"id": {
"type": "long"
}
}
},
"sender": {
"dynamic": "true",
"properties": {
"id": {
"type": "long"
}
}
}
}
},
"messages_count": {
"type": "long"
},
"participants": {
"type": "nested",
"include_in_root": true,
"properties": {
"id": {
"type": "long"
},
"last_received_at": {
"type": "date",
"format": "yyyy-MM-dd'\''T'\''HH:mm:ss'\''Z'\''"
},
"last_sent_at": {
"type": "date",
"format": "yyyy-MM-dd'\''T'\''HH:mm:ss'\''Z'\''"
},
"name": {
"type": "string",
"analyzer": "standard"
}
}
},
"subject": {
"properties": {
"id": {
"type": "long"
},
"name": {
"type": "string"
}
}
}
}
}
}
}'
curl -XPUT "localhost:9200/test-idx/message_thread/1" -d '{
"id" : 1,
"subject" : {"name": "Test Thread"},
"participants" : [
{"id" : 87793, "name" : "John Smith", "last_received_at" : null, "last_sent_at" : "2010-10-27T17:26:58Z"},
{"id" : 3785, "name" : "David Jones", "last_received_at" : "2010-10-27T17:26:58Z", "last_sent_at" : null}
],
"messages" : [{
"id" : 1,
"body" : "This is a test.",
"sender" : { "id" : 87793 },
"recipient" : { "id" : 3785},
"created_at" : "2010-10-27T17:26:58Z"
}]
}'
curl -XPUT "localhost:9200/test-idx/message_thread/2" -d '{
"id" : 2,
"subject" : {"name": "Elastic"},
"participants" : [
{"id" : 57834, "name" : "Paul Johnson", "last_received_at" : "2010-11-25T17:26:58Z", "last_sent_at" : "2010-10-25T17:26:58Z"},
{"id" : 3785, "name" : "David Jones", "last_received_at" : "2010-10-25T17:26:58Z", "last_sent_at" : "2010-11-25T17:26:58Z"}
],
"messages" : [{
"id" : 2,
"body" : "More testing of elasticsearch.",
"sender" : { "id" : 57834 },
"recipient" : { "id" : 3785},
"created_at" : "2010-10-25T17:26:58Z"
},{
"id" : 3,
"body" : "Reply message.",
"sender" : { "id" : 3785 },
"recipient" : { "id" : 57834},
"created_at" : "2010-11-25T17:26:58Z"
}]
}'
curl -XPOST localhost:9200/test-idx/_refresh
echo
# Using include in root
curl "localhost:9200/test-idx/message_thread/_search?pretty=true" -d '{
"query": {
"filtered": {
"query": {
"nested": {
"path": "participants",
"score_mode": "max",
"query": {
"custom_score": {
"query": {
"filtered": {
"query": {
"match_all": {}
},
"filter": {
"term": {
"participants.id": 3785
}
}
}
},
"params": {
"sort_column": "participants.last_received_at"
},
"script": "doc[sort_column].value"
}
}
}
},
"filter": {
"query": {
"multi_match": {
"query": "test",
"fields": ["subject.name", "participants.name", "messages.body"],
"operator": "and",
"use_dis_max": true
}
}
}
}
},
"sort": ["_score"],
"fields": []
}
'
# Not using include in root
curl "localhost:9200/test-idx/message_thread/_search?pretty=true" -d '{
"query": {
"filtered": {
"query": {
"nested": {
"path": "participants",
"score_mode": "max",
"query": {
"custom_score": {
"query": {
"filtered": {
"query": {
"match_all": {}
},
"filter": {
"term": {
"participants.id": 3785
}
}
}
},
"params": {
"sort_column": "participants.last_received_at"
},
"script": "doc[sort_column].value"
}
}
}
},
"filter": {
"query": {
"bool": {
"should": [{
"match": {
"subject.name":"test"
}
}, {
"nested" : {
"path": "participants",
"query": {
"match": {
"name":"test"
}
}
}
}, {
"match": {
"messages.body":"test"
}
}
]
}
}
}
}
},
"sort": ["_score"],
"fields": []
}
'
答案 0 :(得分：0)
这里有几个问题。您询问嵌套对象，但参与者未在映射中定义为嵌套对象。第二个可能的问题是得分具有float类型，因此它可能没有足够的精度来表示时间戳。如果您可以弄清楚如何将此值放入float中，您可以查看此示例：Elastic search - tagging strength (nested/child document boosting)。但是，如果您正在开发新系统，则可能需要谨慎升级到0.90.0.Beta1，它支持在嵌套字段上进行排序。