我对弹性搜索中的聚合有疑问。我有一份如下文件：
{
"_index": "products",
"_type": "product",
"_id": "ID-12345",
"_score": 1,
"_source": {
"created_at": "2017-08-04T17:56:44.592Z",
"updated_at": "2017-08-04T17:56:44.592Z",
"product_information": {
"sku": "12345",
"name": "Product Name",
"price": 25,
"brand": "Brand Name",
"url": "URL"
},
"product_detail": {
"description": "Product description text here.",
"string_facets": [
{
"facet_name": "Colour",
"facet_value": "Grey"
},
{
"facet_name": "Category",
"facet_value": "Linen"
},
{
"facet_name": "Category",
"facet_value": "Throws & Blanket"
},
{
"facet_name": "Keyword",
"facet_value": "Contemporary"
},
{
"facet_name": "Keyword",
"facet_value": "Sophisticated"
}
]
}
}
}
我正在product_detail.string_facets字段中存储颜色，材料，类别和关键字等产品信息。我想将此用于聚合以获取颜色/材质/类别/关键字建议，但作为单独的存储桶。即，product_detail.string_facets.facet_name中定义的每个string_facet类型都有一个单独的存储桶。
这是我目前正在返回数据的查询，但并不像我预期的那样。首先是查询（这只是为了尝试获取颜色）：
{
"from": 0,
"size": 12,
"query": {
"bool": {
"should": [
{
"multi_match": {
"query": "Rug",
"fields": ["product_information.name", "product_detail.string_facets.facet_value"]
}
},
{
"multi_match": {
"query": "Blue",
"fields": ["product_information.name", "product_detail.string_facets.facet_name"]
}
}
],
"minimum_should_match": "100%"
}
},
"aggs": {
"suggestions": {
"filter": { "term": { "product_detail.string_facets.facet_name.keyword": "Colour" }},
"aggs": {
"colours": {
"terms": {
"field": "product_detail.string_facets.facet_value.keyword",
"size": 10
}
}
}
}
}
}
这给我输出如下：
"aggregations": {
"suggestions": {
"doc_count": 21,
"colours": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 23,
"buckets": [
{
"key": "Rug",
"doc_count": 21
},
{
"key": "Blue",
"doc_count": 18
},
{
"key": "Bold",
"doc_count": 7
},
{
"key": "Modern",
"doc_count": 6
},
{
"key": "Multi-Coloured",
"doc_count": 5
},
{
"key": "Contemporary",
"doc_count": 4
},
{
"key": "Traditional",
"doc_count": 4
},
{
"key": "White",
"doc_count": 4
},
{
"key": "Luxurious",
"doc_count": 3
},
{
"key": "Minimal",
"doc_count": 3
}
]
}
}
}
它给了我所有facet_name的结果，而不是我认为的facet_type颜色的结果。
非常感谢任何帮助。 Elasticsearch看起来非常强大，但文档非常令人生畏！
答案 0 :(得分：0)
您没有显示映射的外观，但我认为product_detail.string_facets字段只是一个内部对象字段，这就是您获得此类结果的原因。通过这种类型的映射，Elasticsearch将数组展平为一个简单的字段名称和值列表。在你的情况下它变成：
{
"product_detail.string_facets.facet_name": ["Colour", "Category", "Keyword"],
"product_detail.string_facets.facet_value": ["Grey", "Linen", "Throws & Blanket", "Contemporary", "Sophisticated"]
}
如您所见，基于此结构，Elasticsearch无法知道如何聚合数据。
要使其正常工作，product_detail.string_facets字段应为nested类型。 string_facets的映射应与此类似（注意"type": "nested"）：
"string_facets": {
"type": "nested",
"properties": {
"facet_name": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
},
"facet_value": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore_above": 256
}
}
}
}
}
现在我索引以下文件：
{
"created_at": "2017-08-04T17:56:44.592Z",
"updated_at": "2017-08-04T17:56:44.592Z",
"product_information": {
"sku": "12345",
"name": "Rug",
"price": 25,
"brand": "Brand Name",
"url": "URL"
},
"product_detail": {
"description": "Product description text here.",
"string_facets": [
{
"facet_name": "Colour",
"facet_value": "Blue"
},
{
"facet_name": "Colour",
"facet_value": "Red"
},
{
"facet_name": "Category",
"facet_value": "Throws & Blanket"
},
{
"facet_name": "Keyword",
"facet_value": "Contemporary"
}
]
}
}
现在，要将颜色建议聚合为单独的存储桶，您可以尝试此查询（我简化了bool query以满足我的文档需要）：
{
"from": 0,
"size": 12,
"query": {
"bool": {
"should": [
{
"multi_match": {
"query": "Rug",
"fields": ["product_information.name", "product_detail.string_facets.facet_value"]
}
}
]
}
},
"aggs": {
"facets": {
"nested" : {
"path" : "product_detail.string_facets"
},
"aggs": {
"suggestions": {
"filter": { "term": { "product_detail.string_facets.facet_name.keyword": "Colour" }},
"aggs": {
"colours": {
"terms": {
"field": "product_detail.string_facets.facet_value.keyword",
"size": 10
}
}
}
}
}
}
}
}
结果：
{
...,
"hits": {
...
},
"aggregations": {
"facets": {
"doc_count": 5,
"suggestions": {
"doc_count": 2,
"colours": {
"doc_count_error_upper_bound": 0,
"sum_other_doc_count": 0,
"buckets": [
{
"key": "Blue",
"doc_count": 1
},
{
"key": "Red",
"doc_count": 1
}
]
}
}
}
}
}