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针对结构化或非结构化数据过滤一般搜索

如果您的搜索应用使用结构化数据或带有元数据的非结构化数据，您可以使用元数据过滤搜索查询。当前页面解释了如何使用元数据字段将搜索限制在一组特定的文档。

准备工作

确保您已创建应用并注入了结构化数据或非结构化数据带有元数据的数据。如需了解详情，请参阅创建搜索应用。

元数据示例

请查看这个 4 个 PDF 文件（document_1.pdf、 document_2.pdf、document_3.pdf 和 document_4.pdf）。这些元数据将与 PDF 文件一起放在 Cloud Storage 存储桶的 JSON 文件中。您可以在阅读本页内容时，请再参阅这个示例。

{"id": "1", "structData": {"title": "Policy on accepting corrected claims", "category": ["persona_A"]}, "content": {"mimeType": "application/pdf", "uri": "gs://bucketname_87654321/data/document_1.pdf"}}
{"id": "2", "structData": {"title": "Claims documentation and reporting guidelines for commercial members", "category": ["persona_A", "persona_B"]}, "content": {"mimeType": "application/pdf", "uri": "gs://bucketname_87654321/data/document_2.pdf"}}
{"id": "3", "structData": {"title": "Claims guidelines for bundled services and supplies for commercial members", "category": ["persona_B", "persona_C"]}, "content": {"mimeType": "application/pdf", "uri": "gs://bucketname_87654321/data/document_3.pdf"}}
{"id": "4", "structData": {"title": "Advantage claims submission guidelines", "category": ["persona_A", "persona_C"]}, "content": {"mimeType": "application/pdf", "uri": "gs://bucketname_87654321/data/document_4.pdf"}}

过滤器表达式语法

请确保您了解过滤条件表达式的语法，定义您的搜索过滤器。过滤器表达式语法可总结为以下扩展 Backus - Naur 形式：

  # A single expression or multiple expressions that are joined by "AND" or "OR".
  filter = expression, { " AND " | "OR", expression };
  # Expressions can be prefixed with "-" or "NOT" to express a negation.
  expression = [ "-" | "NOT " ],
    # A parenthetical expression.
    | "(", expression, ")"
    # A simple expression applying to a text field.
    # Function "ANY" returns true if the field exactly matches any of the literals.
    ( text_field, ":", "ANY", "(", literal, { ",", literal }, ")"
    # A simple expression applying to a numerical field. Function "IN" returns true
    # if a field value is within the range. By default, lower_bound is inclusive and
    # upper_bound is exclusive.
    | numerical_field, ":", "IN", "(", lower_bound, ",", upper_bound, ")"
    # A simple expression that applies to a numerical field and compares with a double value.
    | numerical_field, comparison, double
    # An expression that applies to a geolocation field with text/street/postal address.
    |  geolocation_field, ":", "GEO_DISTANCE(", literal, ",", distance_in_meters, ")"
    # An expression that applies to a geolocation field with latitude and longitude.
    | geolocation_field, ":", "GEO_DISTANCE(", latitude_double, ",", longitude_double, ",", distance_in_meters, ")"
    # Datetime field
    | datetime_field, comparison, literal_iso_8601_datetime_format);
  # A lower_bound is either a double or "*", which represents negative infinity.
  # Explicitly specify inclusive bound with the character 'i' or exclusive bound
  # with the character 'e'.
  lower_bound = ( double, [ "e" | "i" ] ) | "*";
  # An upper_bound is either a double or "*", which represents infinity.
  # Explicitly specify inclusive bound with the character 'i' or exclusive bound
  # with the character 'e'.
  upper_bound = ( double, [ "e" | "i" ] ) | "*";
  # Supported comparison operators.
  comparison = "<=" | "<" | ">=" | ">" | "=";
  # A literal is any double quoted string. You must escape backslash (\) and
  # quote (") characters.
  literal = double quoted string;
  text_field = text field - for example, category;
  numerical_field = numerical field - for example, score;
  geolocation_field = field of geolocation data type - for example home_address, location;
  datetime_field = field of datetime data type - for example creation_date, expires_on;
  literal_iso_8601_datetime_format = either a double quoted string representing ISO 8601 datetime or a numerical field representing microseconds from unix epoch.

使用元数据过滤条件进行搜索

如需使用元数据过滤器进行搜索，请按以下步骤操作：

确定用于过滤搜索查询的元数据字段。例如，对于开始前须知中的元数据，您可以使用 category 字段作为搜索过滤条件。用户可以按 persona_A、persona_B 或 persona_C 进行过滤，这样他们的搜索结果就会仅限于与他们感兴趣的角色相关联的文档。
使元数据字段可编入索引：
1. 在 Google Cloud 控制台中，前往 Agent Builder 页面，然后在导航菜单中点击 Apps。
  
  前往“应用”页面
2. 点击您的搜索应用。
3. 在导航菜单中，点击数据。
4. 点击架构标签页。此标签页显示的是当前字段设置。
  
  注意：只有包含结构化数据或包含元数据的非结构化数据的数据存储区才会显示架构标签页。
5. 点击修改。
6. 选中要设为“可编入索引”的字段对应的可编入索引复选框可编入索引。
7. 点击保存。如需了解详情，请参阅配置字段设置。
找到您的数据存储区 ID。如果您已经有数据存储区 ID，请跳至下一步。
1. 在 Google Cloud 控制台中，前往 Agent Builder 页面，然后在导航菜单中，点击 Data Stores。
  
  前往“数据存储区”页面
2. 点击您的数据存储区的名称。
3. 在数据存储区的数据页面上，获取数据存储区 ID。

获取搜索结果。

curl -X POST -H "Authorization: Bearer $(gcloud auth print-access-token)" \
-H "Content-Type: application/json" \
"https://discoveryengine.googleapis.com/v1beta/projects/PROJECT_ID/locations/global/collections/default_collection/dataStores/DATA_STORE_ID/servingConfigs/default_search:search" \
-d '{
"query": "QUERY",
"filter": "FILTER"
}'

PROJECT_ID：您的项目的 ID。
DATA_STORE_ID：您的数据存储区的 ID。
QUERY：要搜索的查询文本。
FILTER：可选。一个文本字段，可让您按过滤器表达式语法。默认值为空字符串，这意味着未应用任何过滤条件。

例如，假设您已按照准备工作部分中的说明导入了四个包含元数据的 PDF 文件。您想搜索包含字词“claims”的文档，并且仅查询 category 值为 persona_A 的文档。为此，您可以将以下声明添加到致电：

"query": "claims",
"filter": "category: ANY(\"persona_A\")"

如需了解详情，请参阅获取包含结构化数据或非结构化数据的应用的搜索结果中的 REST 标签页。

点击查看示例回复。

如果您执行与上文中相似的搜索，则应该会收到类似于以下内容的响应。请注意，响应包含三个具有 category 的文档，值为 persona_A。

{
"results": [
{
  "id": "2",
  "document": {
    "name": "projects/abcdefg/locations/global/collections/default_collection/dataStores/search_store_id/branches/0/documents/2",
    "id": "2",
    "structData": {
      "title": "Claims documentation and reporting guidelines for commercial members",
      "category": [
        "persona_A",
        "persona_B"
      ]
    },
    "derivedStructData": {
      "link": "gs://bucketname_87654321/data/document_2.pdf",
      "extractive_answers": [
        {
          "pageNumber": "1",
          "content": "lorem ipsum"
        }
      ]
    }
  }
},
{
  "id": "1",
  "document": {
    "name": "projects/abcdefg/locations/global/collections/default_collection/dataStores/search_store_id/branches/0/documents/1",
    "id": "1",
    "structData": {
      "title": "Policy on accepting corrected claims",
      "category": [
        "persona_A"
      ]
    },
    "derivedStructData": {
      "extractive_answers": [
        {
          "pageNumber": "2",
          "content": "lorem ipsum"
        }
      ],
      "link": "gs://bucketname_87654321/data/document_1.pdf"
    }
  }
},
{
  "id": "4",
  "document": {
    "name": "projects/abcdefg/locations/global/collections/default_collection/dataStores/search_store_id/branches/0/documents/4",
    "id": "4",
    "structData": {
      "title": "Advantage claims submission guidelines",
      "category": [
        "persona_A",
        "persona_C"
      ]
    },
    "derivedStructData": {
      "extractive_answers": [
        {
          "pageNumber": "47",
          "content": "lorem ipsum"
        }
      ],
      "link": "gs://bucketname_87654321/data/document_4.pdf"
    }
  }
}
],
"totalSize": 330,
"attributionToken": "UvBRCgsI26PxpQYQs7vQZRIkNjRiYWY1MTItMDAwMC0yZWIwLTg3MTAtMTQyMjNiYzYzMWEyIgdHRU5FUklDKhSOvp0VpovvF8XL8xfC8J4V1LKdFQ",
"guidedSearchResult": {},
"summary": {}
}

过滤表达式示例

下表提供了过滤表达式的示例。

过滤	仅返回满足以下条件的文档的结果：
`category: ANY(\"persona_A\")`	文本字段 `category` 为 `persona_A`
`score: IN(*, 100.0e)`	数值字段 `score` 大于负无穷大且小于 100.0
`non-smoking = \"true\"`	布尔值 `non-smoking` 为 true
`pet-friendly = \"false\"`	布尔值 `pet-friendly` 为 false
`manufactured_date = \"2023\"`	`manufactured date` 是 2023 年的任意时间
`manufactured_date >= \"2024-04-16\"`	`manufactured_date` 不早于 2024 年 4 月 16 日
`manufactured_date < \"2024-04-16T12:00:00-07:00\"`	`manufactured_date` 在 2024 年 4 月 16 日（太平洋夏令时间）中午之前
`office.location:GEO_DISTANCE(\"1600 Amphitheater Pkwy, Mountain View, CA, 94043\", 500)`	地理定位字段 `office.location` 在距离 1600 Amphitheater Pkwy 不超过 500 米的距离内
`NOT office.location:GEO_DISTANCE(\"Palo Alto, CA\", 1000)`	地理位置字段 `office.location` 不在加利福尼亚州帕洛阿尔托市 1 公里半径范围内。
`office.location:GEO_DISTANCE(34.1829, -121.293, 500)`	地理位置字段 `office.location` 位于纬度 34.1829 和经度 -121.293 的 500 米半径范围内
`category: ANY(\"persona_A\") AND score: IN(*, 100.0e)`	`category` 为 `persona_A`，且 `score` 小于 100
`office.location:GEO_DISTANCE(\"Mountain View, CA\", 500) OR office.location:GEO_DISTANCE(\"Palo Alto, CA\", 500)`	`office.location` 距离山景谷或帕洛阿尔托不超过 500 米。
`(price<175 AND pet-friendly = \"true\") OR (price<125 AND pet-friendly = \"false\")`	`price` 低于 175 且我可以带我的宠物，或者 `price` 低于 125 且我不能带我的宠物

后续步骤

要了解过滤条件对搜索质量的影响评估搜索质量。如需了解详情，请参阅评估搜索质量。