嵌套查询 #

nested 查询充当其他查询的包装器，用于搜索嵌套字段。嵌套字段对象被视为单独的文档进行搜索。如果对象匹配搜索条件， nested 查询将返回根级别的父文档。

参考样例 #

在运行 nested 查询之前，您的索引必须包含一个嵌套字段。

要配置一个包含嵌套字段的示例索引，请发送以下请求：

PUT /testindex
{
  "mappings": {
    "properties": {
      "patient": {
        "type": "nested",
        "properties": {
          "name": {
            "type": "text"
          },
          "age": {
            "type": "integer"
          }
        }
      }
    }
  }
}

接下来，将一个文档索引到示例索引中：

PUT /testindex/_doc/1
{
  "patient": {
    "name": "John Doe",
    "age": 56
  }
}

要搜索嵌套的 patient 字段，请将您的查询包裹在 nested 查询中，并提供 path 给嵌套字段：

GET /testindex/_search
{
  "query": {
    "nested": {
      "path": "patient",
      "query": {
        "match": {
          "patient.name": "John"
        }
      }
    }
  }
}

查询返回匹配的文档：

{
  "took": 3,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 1,
      "relation": "eq"
    },
    "max_score": 0.2876821,
    "hits": [
      {
        "_index": "testindex",
        "_id": "1",
        "_score": 0.2876821,
        "_source": {
          "patient": {
            "name": "John Doe",
            "age": 56
          }
        }
      }
    ]
  }
}

检索内部命中项 #

要返回与查询匹配的内部命中，请提供 inner_hits 参数：

GET /testindex/_search
{
  "query": {
    "nested": {
      "path": "patient",
      "query": {
        "match": {
          "patient.name": "John"
        }
      },
      "inner_hits": {}
    }
  }
}

结果包含额外的 inner_hits 字段。 _nested 字段标识了内部命中来源的具体内部对象。它包含嵌套命中及其相对于 _source 中位置的偏移量。由于排序和评分， inner_hits 中命中对象的位置通常与其在嵌套对象中的原始位置不同。

默认情况下，返回的击中对象中的 _source 相对于 inner_hits 字段。在这个例子中， inner_hits 中的 _source 包含 name 和 age 字段，而不是顶层的 _source ，后者包含整个 patient 对象：

{
  "took": 38,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 1,
      "relation": "eq"
    },
    "max_score": 0.2876821,
    "hits": [
      {
        "_index": "testindex",
        "_id": "1",
        "_score": 0.2876821,
        "_source": {
          "patient": {
            "name": "John Doe",
            "age": 56
          }
        },
        "inner_hits": {
          "patient": {
            "hits": {
              "total": {
                "value": 1,
                "relation": "eq"
              },
              "max_score": 0.2876821,
              "hits": [
                {
                  "_index": "testindex",
                  "_id": "1",
                  "_nested": {
                    "field": "patient",
                    "offset": 0
                  },
                  "_score": 0.2876821,
                  "_source": {
                    "name": "John Doe",
                    "age": 56
                  }
                }
              ]
            }
          }
        }
      }
    ]
  }
}

多级嵌套查询 #

您可以使用多级嵌套查询来搜索包含在其他嵌套对象内部的嵌套对象。在这个例子中，您将通过为层次结构的每一级指定嵌套查询来查询多个层级的嵌套字段。

首先，创建一个具有多级嵌套字段的索引：

PUT /patients
{
  "mappings": {
    "properties": {
      "patient": {
        "type": "nested",
        "properties": {
          "name": {
            "type": "text"
          },
          "contacts": {
            "type": "nested",
            "properties": {
              "name": {
                "type": "text"
              },
              "relationship": {
                "type": "text"
              },
              "phone": {
                "type": "keyword"
              }
            }
          }
        }
      }
    }
  }
}

接下来，将一个文档索引到示例索引中：

PUT /patients/_doc/1
{
  "patient": {
    "name": "John Doe",
    "contacts": [
      {
        "name": "Jane Doe",
        "relationship": "mother",
        "phone": "5551111"
      },
      {
        "name": "Joe Doe",
        "relationship": "father",
        "phone": "5552222"
      }
    ]
  }
}

要搜索嵌套的 patient 字段，请使用多级 nested 查询。以下查询搜索联系信息中包含名为 Jane 且关系为 mother 的人的病人：

GET /patients/_search
{
  "query": {
    "nested": {
      "path": "patient",
      "query": {
        "nested": {
          "path": "patient.contacts",
          "query": {
            "bool": {
              "must": [
                { "match": { "patient.contacts.relationship": "mother" } },
                { "match": { "patient.contacts.name": "Jane" } }
              ]
            }
          }
        }
      }
    }
  }
}

查询返回具有匹配这些详细信息的联系记录的患者：

{
  "took": 14,
  "timed_out": false,
  "_shards": {
    "total": 1,
    "successful": 1,
    "skipped": 0,
    "failed": 0
  },
  "hits": {
    "total": {
      "value": 1,
      "relation": "eq"
    },
    "max_score": 1.3862942,
    "hits": [
      {
        "_index": "patients",
        "_id": "1",
        "_score": 1.3862942,
        "_source": {
          "patient": {
            "name": "John Doe",
            "contacts": [
              {
                "name": "Jane Doe",
                "relationship": "mother",
                "phone": "5551111"
              },
              {
                "name": "Joe Doe",
                "relationship": "father",
                "phone": "5552222"
              }
            ]
          }
        }
      }
    ]
  }
}

参数说明 #

以下表格列出了所有由 nested 查询支持的一级参数。