过滤结构化或非结构化数据的通用搜索结果

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。本页介绍了如何使用元数据字段将搜索范围限制为一组特定文档。

准备工作

确保您已创建应用并提取结构化数据或包含元数据的非结构化数据。如需了解详情，请参阅创建搜索应用。

元数据示例

查看以下四个 PDF 文件（document_1.pdf、document_2.pdf、document_3.pdf 和 document_4.pdf）的元数据示例。这些元数据将与 PDF 文件一起存储在 Cloud Storage 存储桶中的 JSON 文件中。阅读本页内容时，您可以随时参考此示例。

{"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

请务必了解您将用于定义搜索过滤条件的过滤表达式的语法。过滤条件表达式语法可按以下扩展巴科斯范式总结：

  # 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条件进行搜索，请按以下步骤操作：

1. 确定要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。

2. 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。此标签页会显示当前的字段设置。

   5. 点击修改。

   6. 为您要将其设为可编入索引的字段选中可编入索引复选框。

   7. 点击保存。如需了解详情，请参阅配置字段设置。

3. 找到您的数据存储区 ID。如果您已拥有数据存储区 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数据存储区。

      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。

4. 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：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，可让您使用过滤条件表达式语法按指定的一组字段进行过滤。默认值为空字符串，表示不应用过滤条件。

   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，您需要在调用中添加以下语句：

   "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 category 值为 persona_A 的三个文档。

   {
   "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。

后续步骤

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