检索内部命中
在 UDB-SX 中，当您使用嵌套对象或父子关联进行搜索时，底层的命中（嵌套内部对象或子文档）默认是隐藏的。您可以使用搜索查询中的 inner_hits 参数来检索内部命中。
您还可以将 inner_hits 与以下功能结合使用：
解释
嵌套对象的内部命中
嵌套对象允许您索引对象数组并在同一文档内保持它们的关系。以下示例请求使用 inner_hits 参数检索底层的内部命中。
创建包含嵌套对象的索引映射：
PUT /my_index { "mappings": { "properties": { "user": { "type": "nested", "properties": { "name": { "type": "text" }, "age": { "type": "integer" } } } } } }索引数据：
POST /my_index/_doc/1 { "group": "fans", "user": [ { "name": "John Doe", "age": 28 }, { "name": "Jane Smith", "age": 34 } ] }使用
inner_hits进行查询：GET /my_index/_search { "query": { "nested": { "path": "user", "query": { "bool": { "must": [ { "match": { "user.name": "John" } } ] } }, "inner_hits": {} } } }
上述查询搜索包含名称 John 的嵌套用户对象，并在响应的 inner_hits 部分返回匹配的嵌套文档：
{
"hits" : {
"total" : {
"value" : 1,
"relation" : "eq"
},
"max_score" : 0.6931471,
"hits" : [
{
"_index" : "my_index",
"_id" : "1",
"_score" : 0.6931471,
"_source" : {
"group" : "fans",
"user" : [
{
"name" : "John Doe",
"age" : 28
},
{
"name" : "Jane Smith",
"age" : 34
}
]
},
"inner_hits" : {
"user" : {
"hits" : {
"total" : {
"value" : 1,
"relation" : "eq"
},
"max_score" : 0.6931471,
"hits" : [
{
"_index" : "my_index",
"_id" : "1",
"_nested" : {
"field" : "user",
"offset" : 0
},
"_score" : 0.6931471,
"_source" : {
"name" : "John Doe",
"age" : 28
}
}
]
}
}
}
}
]
}
}
父子关联对象的内部命中
父子关联关系允许您在同一索引内创建不同类型文档之间的关系。以下示例请求使用父子关联对象搜索 inner_hits。
创建包含父子关联字段的索引：
PUT /my_index { "mappings": { "properties": { "my_join_field": { "type": "join", "relations": { "parent": "child" } }, "text": { "type": "text" } } } }索引数据：
# 索引父文档 PUT /my_index/_doc/1 { "text": "This is a parent document", "my_join_field": "parent" } # 索引子文档 PUT /my_index/_doc/2?routing=1 { "text": "This is a child document", "my_join_field": { "name": "child", "parent": "1" } }使用
inner_hits进行搜索：GET /my_index/_search { "query": { "has_child": { "type": "child", "query": { "match": { "text": "child" } }, "inner_hits": {} } } }
上述查询搜索具有匹配查询条件（在此情况下，包含术语 "child"）的子文档的父文档。它在响应的 inner_hits 部分返回匹配的子文档：
{
"hits" : {
"total" : {
"value" : 1,
"relation" : "eq"
},
"max_score" : 1.0,
"hits" : [
{
"_index" : "my_index",
"_id" : "1",
"_score" : 1.0,
"_source" : {
"text" : "This is a parent document",
"my_join_field" : "parent"
},
"inner_hits" : {
"child" : {
"hits" : {
"total" : {
"value" : 1,
"relation" : "eq"
},
"max_score" : 0.6931471,
"hits" : [
{
"_index" : "my_index",
"_id" : "2",
"_score" : 0.6931471,
"_routing" : "1",
"_source" : {
"text" : "This is a child document",
"my_join_field" : {
"name" : "child",
"parent" : "1"
}
}
}
]
}
}
}
}
]
}
}
同时使用父子关联和嵌套对象与 inner_hits
以下示例演示了同时使用父子关联和嵌套对象与 inner_hits。
创建具有以下映射的索引：
PUT /my_index { "mappings": { "properties": { "my_join_field": { "type": "join", "relations": { "parent": "child" } }, "text": { "type": "text" }, "comments": { "type": "nested", "properties": { "user": { "type": "text" }, "message": { "type": "text" } } } } } }索引数据：
# 索引父文档 PUT /my_index/_doc/1 { "text": "This is a parent document", "my_join_field": "parent" } # 索引包含嵌套评论的子文档 PUT /my_index/_doc/2?routing=1 { "text": "This is a child document", "my_join_field": { "name": "child", "parent": "1" }, "comments": [ { "user": "John", "message": "This is a comment" }, { "user": "Jane", "message": "Another comment" } ] }使用
inner_hits进行查询：GET /my_index/_search { "query": { "has_child": { "type": "child", "query": { "nested": { "path": "comments", "query": { "bool": { "must": [ { "match": { "comments.user": "John" } } ] } }, "inner_hits": {} } }, "inner_hits": {} } } }
上述查询搜索具有包含 John 所作评论的子文档的父文档。指定 inner_hits 确保返回匹配的子文档及其嵌套评论：
{
"hits" : {
"total" : {
"value" : 1,
"relation" : "eq"
},
"max_score" : 1.0,
"hits" : [
{
"_index" : "my_index",
"_id" : "1",
"_score" : 1.0,
"_source" : {
"text" : "This is a parent document",
"my_join_field" : "parent"
},
"inner_hits" : {
"child" : {
"hits" : {
"total" : {
"value" : 1,
"relation" : "eq"
},
"max_score" : 0.6931471,
"hits" : [
{
"_index" : "my_index",
"_id" : "2",
"_score" : 0.6931471,
"_routing" : "1",
"_source" : {
"text" : "This is a child document",
"my_join_field" : {
"name" : "child",
"parent" : "1"
},
"comments" : [
{
"user" : "John",
"message" : "This is a comment"
},
{
"user" : "Jane",
"message" : "Another comment"
}
]
},
"inner_hits" : {
"comments" : {
"hits" : {
"total" : {
"value" : 1,
"relation" : "eq"
},
"max_score" : 0.6931471,
"hits" : [
{
"_index" : "my_index",
"_id" : "2",
"_nested" : {
"field" : "comments",
"offset" : 0
},
"_score" : 0.6931471,
"_source" : {
"message" : "This is a comment",
"user" : "John"
}
}
]
}
}
}
}
]
}
}
}
}
]
}
}
inner_hits 参数
您可以在使用嵌套对象和父子关联关系的搜索中传递以下附加参数给 inner_hits：
from：从inner_hits结果中开始获取命中的偏移量。size：要返回的内部命中的最大数量。sort：内部命中的排序顺序。name：响应中内部命中的自定义名称。这在区分单个查询中的多个内部命中时很有用。
示例：嵌套对象的 inner_hits 参数
创建具有以下映射的索引：
PUT /products { "mappings": { "properties": { "product_name": { "type": "text" }, "reviews": { "type": "nested", "properties": { "user": { "type": "text" }, "comment": { "type": "text" }, "rating": { "type": "integer" } } } } } }索引数据：
POST /products/_doc/1 { "product_name": "Smartphone", "reviews": [ { "user": "Alice", "comment": "Great phone", "rating": 5 }, { "user": "Bob", "comment": "Not bad", "rating": 3 }, { "user": "Charlie", "comment": "Excellent", "rating": 4 } ] }POST /products/_doc/2 { "product_name": "Laptop", "reviews": [ { "user": "Dave", "comment": "Very good", "rating": 5 }, { "user": "Eve", "comment": "Good value", "rating": 4 } ] }使用
inner_hits并提供附加参数进行查询：GET /products/_search { "query": { "nested": { "path": "reviews", "query": { "match": { "reviews.comment": "Good" } }, "inner_hits": { "from": 0, "size": 2, "sort": [ { "reviews.rating": { "order": "desc" } } ], "name": "top_reviews" } } } }
预期结果如下：
{
"hits" : {
"total" : {
"value" : 1,
"relation" : "eq"
},
"max_score" : 0.83740485,
"hits" : [
{
"_index" : "products",
"_id" : "2",
"_score" : 0.83740485,
"_source" : {
"product_name" : "Laptop",
"reviews" : [
{
"user" : "Dave",
"comment" : "Very good",
"rating" : 5
},
{
"user" : "Eve",
"comment" : "Good value",
"rating" : 4
}
]
},
"inner_hits" : {
"top_reviews" : {
"hits" : {
"total" : {
"value" : 2,
"relation" : "eq"
},
"max_score" : null,
"hits" : [
{
"_index" : "products",
"_id" : "2",
"_nested" : {
"field" : "reviews",
"offset" : 0
},
"_score" : null,
"_source" : {
"rating" : 5,
"comment" : "Very good",
"user" : "Dave"
},
"sort" : [
5
]
},
{
"_index" : "products",
"_id" : "2",
"_nested" : {
"field" : "reviews",
"offset" : 1
},
"_score" : null,
"_source" : {
"rating" : 4,
"comment" : "Good value",
"user" : "Eve"
},
"sort" : [
4
]
}
]
}
}
}
}
]
}
}
示例：父子关联关系的 inner_hits 参数
创建具有以下映射的索引：
PUT /company { "mappings": { "properties": { "my_join_field": { "type": "join", "relations": { "employee": "task" } }, "name": { "type": "text" }, "description": { "type": "text", "fields": { "keyword": { "type": "keyword" } } } } } }索引数据：
# 索引父文档 PUT /company/_doc/1 { "name": "Alice", "my_join_field": "employee" }# 索引子文档 PUT /company/_doc/2?routing=1 { "description": "Complete the project", "my_join_field": { "name": "task", "parent": "1" } }PUT /company/_doc/3?routing=1 { "description": "Prepare the report", "my_join_field": { "name": "task", "parent": "1" } }PUT /company/_doc/4?routing=1 { "description": "Update project", "my_join_field": { "name": "task", "parent": "1" } }使用
inner_hits参数进行查询：GET /company/_search { "query": { "has_child": { "type": "task", "query": { "match": { "description": "project" } }, "inner_hits": { "from": 0, "size": 10, "sort": [ { "description.keyword": { "order": "asc" } } ], "name": "related_tasks" } } } }
预期结果如下：
{
"hits" : {
"total" : {
"value" : 1,
"relation" : "eq"
},
"max_score" : 1.0,
"hits": [
{
"_index": "company",
"_id": "1",
"_score": 1,
"_source": {
"name": "Alice",
"my_join_field": "employee"
},
"inner_hits": {
"related_tasks": {
"hits": {
"total": {
"value": 2,
"relation": "eq"
},
"max_score": null,
"hits": [
{
"_index": "company",
"_id": "2",
"_score": null,
"_routing": "1",
"_source": {
"description": "Complete the project",
"my_join_field": {
"name": "task",
"parent": "1"
}
},
"sort": [
"Complete the project"
]
},
{
"_index": "company",
"_id": "4",
"_score": null,
"_routing": "1",
"_source": {
"description": "Update project",
"my_join_field": {
"name": "task",
"parent": "1"
}
},
"sort": [
"Update project"
]
}
]
}
}
}
}
]
}
}
使用 inner_hits 的好处
详细的查询结果
您可以使用
inner_hits从父文档的搜索结果中检索有关匹配的嵌套或子文档的详细信息。这对于理解匹配的上下文和细节特别有用，而无需执行额外的查询。示例用例：在博客文章索引中，您将评论作为嵌套对象。当搜索包含特定评论的博客文章时，您可以检索与搜索条件匹配的相关评论以及有关帖子的信息。
优化性能
如果没有
inner_hits，您可能需要运行多个查询来获取相关文档。使用inner_hits将这些查询合并为一个查询，减少了往返 UDB-SX 服务器的次数，并提高了整体性能。示例用例：在电子商务应用程序中，您有产品作为父文档和评论作为子文档。使用
inner_hits的单个查询可以获取产品及其相关评论，避免了多个单独的查询。简化查询逻辑
您可以在单个查询中组合父/子或嵌套文档逻辑，以简化应用程序代码并降低复杂性。这有助于通过将查询逻辑集中在 UDB-SX 中来确保代码更易于维护和一致。
示例用例：在求职门户网站中，您有职位作为父文档和申请作为嵌套或子文档。您可以通过在一个查询中获取职位和特定申请来简化应用程序逻辑。
上下文相关性
使用
inner_hits通过显示确切匹配查询条件的嵌套或子文档来提供上下文相关性。这对于结果相关性依赖于匹配查询的文档特定部分的应用至关重要。示例用例：在客户支持系统中，您有工单作为父文档和评论或更新作为嵌套或子文档。您可以确定哪个特定评论与搜索匹配，以便更好地理解工单搜索的上下文。