我有一个包含多个字段的索引。我想根据所有字段中搜索字符串的存在进行过滤，除了一个 - 用户评论 .
我正在做的查询搜索是
{
"from": offset,
"size": limit,
"_source": [
"document_title"
],
"query": {
"function_score": {
"query": {
"bool": {
"must":
{
"query_string": {
"query": "#{query}"
}
}
}
}
}
}
}
尽管查询字符串正在搜索所有字段，并在 中为我提供了具有匹配字符串的文档用户评论场也是如此。但是，我想针对所有不包含 的字段进行查询。用户评论 field 。
白名单是一个非常大的列表，而且字段的名称是动态的，因此使用 fields 参数提及白名单字段列表是不可行的。
"query_string": {
"query": "#{query}",
"fields": [
"document_title",
"field2"
]
}
任何人都可以提出一个关于如何从搜索中排除字段的想法吗？
最佳答案
有一种方法可以让它工作，它不是很漂亮，但可以完成工作。您可以使用 boost 实现您的目标。和 multifield query_string的参数, bool 查询以结合分数和设置 min_score :
POST my-query-string/doc/_search
{
"query": {
"bool": {
"should": [
{
"query_string": {
"query": "#{query}",
"type": "most_fields",
"boost": 1
}
},
{
"query_string": {
"fields": [
"comments"
],
"query": "#{query}",
"boost": -1
}
}
]
}
},
"min_score": 0.00001
}
假设您有以下一组文档:
PUT my-query-string/doc/1
{
"title": "Prodigy in Bristol",
"text": "Prodigy in Bristol",
"comments": "Prodigy in Bristol"
}
PUT my-query-string/doc/2
{
"title": "Prodigy in Birmigham",
"text": "Prodigy in Birmigham",
"comments": "And also in Bristol"
}
PUT my-query-string/doc/3
{
"title": "Prodigy in Birmigham",
"text": "Prodigy in Birmigham and Bristol",
"comments": "And also in Cardiff"
}
PUT my-query-string/doc/4
{
"title": "Prodigy in Birmigham",
"text": "Prodigy in Birmigham",
"comments": "And also in Cardiff"
}
在 Elasticsearch 中，搜索结果按 relevance
_score 排序，分数越大越好。所以让我们尝试 boost下
"comments"字段，因此它对相关性分数的影响被忽略。我们可以通过将两个查询与 should 结合来实现这一点。并使用负值 boost :POST my-query-string/doc/_search
{
"query": {
"bool": {
"should": [
{
"query_string": {
"query": "Bristol"
}
},
{
"query_string": {
"fields": [
"comments"
],
"query": "Bristol",
"boost": -1
}
}
]
}
}
}
{
"hits": {
"total": 3,
"max_score": 0.2876821,
"hits": [
{
"_index": "my-query-string",
"_type": "doc",
"_id": "3",
"_score": 0.2876821,
"_source": {
"title": "Prodigy in Birmigham",
"text": "Prodigy in Birmigham and Bristol",
"comments": "And also in Cardiff"
}
},
{
"_index": "my-query-string",
"_type": "doc",
"_id": "2",
"_score": 0,
"_source": {
"title": "Prodigy in Birmigham",
"text": "Prodigy in Birmigham",
"comments": "And also in Bristol"
}
},
{
"_index": "my-query-string",
"_type": "doc",
"_id": "1",
"_score": 0,
"_source": {
"title": "Prodigy in Bristol",
"text": "Prodigy in Bristol",
"comments": "Prodigy in Bristol",
"discount_percent": 10
}
}
]
}
}
以下是 Elasticsearch 的计算方式
_score在这种情况下:_score = max(title:"Bristol", text:"Bristol", comments:"Bristol") - comments:"Bristol"
文档 1 匹配
comments:"Bristol"部分，它也恰好是最好的分数。根据我们的公式，结果分数为 0。我们实际上想要做的是提升第一个子句(带有“所有”字段)更多 如果匹配更多字段。
我们可以提升吗
query_string匹配更多字段？我们可以，
query_string在 multifield模式有一个 type参数就是这样做的。查询将如下所示:POST my-query-string/doc/_search
{
"query": {
"bool": {
"should": [
{
"query_string": {
"type": "most_fields",
"query": "Bristol"
}
},
{
"query_string": {
"fields": [
"comments"
],
"query": "Bristol",
"boost": -1
}
}
]
}
}
}
{
"hits": {
"total": 3,
"max_score": 0.57536423,
"hits": [
{
"_index": "my-query-string",
"_type": "doc",
"_id": "1",
"_score": 0.57536423,
"_source": {
"title": "Prodigy in Bristol",
"text": "Prodigy in Bristol",
"comments": "Prodigy in Bristol",
"discount_percent": 10
}
},
{
"_index": "my-query-string",
"_type": "doc",
"_id": "3",
"_score": 0.2876821,
"_source": {
"title": "Prodigy in Birmigham",
"text": "Prodigy in Birmigham and Bristol",
"comments": "And also in Cardiff"
}
},
{
"_index": "my-query-string",
"_type": "doc",
"_id": "2",
"_score": 0,
"_source": {
"title": "Prodigy in Birmigham",
"text": "Prodigy in Birmigham",
"comments": "And also in Bristol"
}
}
]
}
}
_score = sum(title:"Bristol", text:"Bristol", comments:"Bristol") - comments:"Bristol"
所以文档匹配
"Bristol"在任何领域都被选中。 comments:"Bristol" 的相关性得分被淘汰了，只有匹配的文档 title:"Bristol"或 text:"Bristol"得到了 _score > 0。我们可以过滤掉那些分数不理想的结果吗？
是的，我们可以，使用
min_score :POST my-query-string/doc/_search
{
"query": {
"bool": {
"should": [
{
"query_string": {
"query": "Bristol",
"type": "most_fields",
"boost": 1
}
},
{
"query_string": {
"fields": [
"comments"
],
"query": "Bristol",
"boost": -1
}
}
]
}
},
"min_score": 0.00001
}
"Bristol" 文档的分数将为 0匹配字段 "comments" only 并且不匹配任何其他字段。输出将是:
{
"hits": {
"total": 2,
"max_score": 0.57536423,
"hits": [
{
"_index": "my-query-string",
"_type": "doc",
"_id": "1",
"_score": 0.57536423,
"_source": {
"title": "Prodigy in Bristol",
"text": "Prodigy in Bristol",
"comments": "Prodigy in Bristol",
"discount_percent": 10
}
},
{
"_index": "my-query-string",
"_type": "doc",
"_id": "3",
"_score": 0.2876821,
"_source": {
"title": "Prodigy in Birmigham",
"text": "Prodigy in Birmigham and Bristol",
"comments": "And also in Cardiff"
}
}
]
}
}
当然。我实际上不建议使用
_score调整，因为这是一个非常复杂的问题。我建议获取现有映射并构建一个字段列表以预先运行查询，这将使代码更加简单明了。
答案中提出的原始解决方案(保留历史记录)
最初建议使用这种查询，其意图与上述解决方案完全相同:
POST my-query-string/doc/_search
{
"query": {
"function_score": {
"query": {
"bool": {
"must": {
"query_string": {
"fields" : ["*", "comments^0"],
"query": "#{query}"
}
}
}
}
}
},
"min_score": 0.00001
}
"fields": ["*"]
关于elasticsearch - 如何从elasticsearch 6.1搜索中排除字段？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/52757277/