恐怕这不可能，因为领域labels不是 ES 保存或创建倒排索引的字段。
Doc doc['fieldname']仅适用于创建倒排索引的字段，Elasticsearch 的 Query DSL 也仅适用于创建倒排索引的字段，不幸的是nested类型不是创建倒排索引的有效字段。
话虽如此，我有以下两种方法可以做到这一点。
为了简单起见，我创建了示例映射、文档和两个可能对您有所帮助的解决方案。
Mapping:
PUT my_sample_index
{
"mappings": {
"properties": {
"myfield": {
"type": "nested",
"properties": {
"label": {
"type": "keyword"
}
}
}
}
}
}
样本文件：
// single field inside 'myfield'
POST my_sample_index/_doc/1
{
"myfield": {
"label": ["New York", "LA", "Austin"]
}
}
// two fields inside 'myfield'
POST my_sample_index/_doc/2
{
"myfield": {
"label": ["London", "Leicester", "Newcastle", "Liverpool"],
"country": "England"
}
}
解决方案1：使用脚本字段（在应用程序级别进行管理）
我有一个解决方法可以得到你想要的东西，虽然不完全是，但可以帮助你过滤掉你的服务层或应用程序。
POST my_sample_index/_search
{
"_source": "*",
"query": {
"bool": {
"must": [
{
"match_all": {}
}
]
}
},
"script_fields": {
"label_size": {
"script": {
"lang": "painless",
"source": "params['_source']['labels'].size() > 1"
}
}
}
}
您会注意到，作为响应，有一个单独的字段label_size被创建为true or false value.
响应示例如下所示：
{
"took" : 5,
"timed_out" : false,
"_shards" : {
"total" : 1,
"successful" : 1,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : {
"value" : 2,
"relation" : "eq"
},
"max_score" : 1.0,
"hits" : [
{
"_index" : "my_sample_index",
"_type" : "_doc",
"_id" : "1",
"_score" : 1.0,
"_source" : {
"myfield" : {
"label" : [
"New York",
"LA",
"Austin"
]
}
},
"fields" : {
"label_size" : [ <---- Scripted Field
false
]
}
},
{
"_index" : "my_sample_index",
"_type" : "_doc",
"_id" : "2",
"_score" : 1.0,
"_source" : {
"myfield" : {
"country" : "England",
"label" : [
"London",
"Leicester",
"Newcastle",
"Liverpool"
]
}
},
"fields" : { <---- Scripted Field
"label_size" : [
true <---- True because it has two fields 'labels' and 'country'
]
}
}
]
}
}
请注意，只有第二个文档才有意义，因为它有两个字段，即country and labels。但是，如果您只想使用以下文档label_size with true，这必须在您的应用程序层进行管理。
解决方案2：重新索引与 labels.size 使用脚本处理器
创建一个新索引，如下所示：
PUT my_sample_index_temp
{
"mappings": {
"properties": {
"myfield": {
"type": "nested",
"properties": {
"label": {
"type": "keyword"
}
}
},
"labels_size":{ <---- New Field where we'd store the size
"type": "integer"
}
}
}
}
创建以下管道：
PUT _ingest/pipeline/set_labels_size
{
"description": "sets the value of labels size",
"processors": [
{
"script": {
"source": """
ctx.labels_size = ctx.myfield.size();
"""
}
}
]
}
使用 Reindex API 重新索引my_sample_index index
POST _reindex
{
"source": {
"index": "my_sample_index"
},
"dest": {
"index": "my_sample_index_temp",
"pipeline": "set_labels_size"
}
}
验证文件my_sample_index_temp using GET my_sample_index_temp/_search
{
"took" : 1,
"timed_out" : false,
"_shards" : {
"total" : 1,
"successful" : 1,
"skipped" : 0,
"failed" : 0
},
"hits" : {
"total" : {
"value" : 2,
"relation" : "eq"
},
"max_score" : 1.0,
"hits" : [
{
"_index" : "my_sample_index_temp",
"_type" : "_doc",
"_id" : "1",
"_score" : 1.0,
"_source" : {
"labels_size" : 1, <---- New Field Created
"myfield" : {
"label" : [
"New York",
"LA",
"Austin"
]
}
}
},
{
"_index" : "my_sample_index_temp",
"_type" : "_doc",
"_id" : "2",
"_score" : 1.0,
"_source" : {
"labels_size" : 2, <----- New Field Created
"myfield" : {
"country" : "England",
"label" : [
"London",
"Leicester",
"Newcastle",
"Liverpool"
]
}
}
}
]
}
}
现在您可以简单地使用这个字段labels_size在你的查询中，它的方式更容易，更不用说高效了。
希望这可以帮助！
