SQL 服务器对具有别名的列进行全文搜索

Question

我正在使用全文搜索，它在 table 的直接列上运行正常，但在 derived/aliased 列上运行不正常。

SELECT ExpectationId
    ,ExpectationName
    ,(
       CASE 
          WHEN ExpectationOrganization_OrganizationId IS NOT NULL
                THEN (
                       SELECT OrganizationName
                       FROM Organizations
                       WHERE OrganizationId = ExpectationOrganization_OrganizationId
                       )
          WHEN ExpectationBeneficiary_BeneficiaryId IS NOT NULL
                THEN (
                       SELECT BeneficiaryName
                       FROM Beneficiaries
                       WHERE BeneficiaryId = ExpectationBeneficiary_BeneficiaryId
                       )
          ELSE (
                    SELECT TeamName
                    FROM Teams
                    WHERE TeamId = ExpectationTeam_TeamId
                    )
          END
       ) AS ParentName
FROM Expectations
WHERE
    FREETEXT(ExpectationName, @Keyword) ---Working
    OR FREETEXT(ParentName, @Keyword) ---Not working

所有这些列 ExpectationName、OrganizationName、BeneficiaryName、TeamName 都是全文索引。

我怎样才能让它适用于 ParentName 列？

Answer 1

您需要先根据您的查询创建一个 VIEW，然后向其中添加一个 Full-Text 索引，其中将包含 ParentName 列。如果没有搜索列的 Full-Text 索引，FREETEXT 和 CONTAINS 都不起作用。

类似的内容应该对您有所帮助：

CREATE VIEW ExpectationsView AS
SELECT ExpectationId
    ,ExpectationName
    ,(
       CASE 
          WHEN ExpectationOrganization_OrganizationId IS NOT NULL
                THEN (
                       SELECT OrganizationName
                       FROM Organizations
                       WHERE OrganizationId = ExpectationOrganization_OrganizationId
                       )
          WHEN ExpectationBeneficiary_BeneficiaryId IS NOT NULL
                THEN (
                       SELECT BeneficiaryName
                       FROM Beneficiaries
                       WHERE BeneficiaryId = ExpectationBeneficiary_BeneficiaryId
                       )
          ELSE (
                    SELECT TeamName
                    FROM Teams
                    WHERE TeamId = ExpectationTeam_TeamId
                    )
          END
       ) AS ParentName
FROM Expectations
GO

-- This index is needed for FTS index.
-- Note, I trust ExpectationId column is unique in your SELECT above,
-- if it's not, the below CREATE INDEX will fail and you will need to provide 
-- a new column to your VIEW which will uniquely identify each row, then use 
-- that PK-like column in the below index
CREATE UNIQUE CLUSTERED INDEX PK_ExpectationsView   
    ON ExpectationsView (ExpectationId);  
GO  

CREATE FULLTEXT CATALOG fts_catalog;  
GO  
CREATE FULLTEXT INDEX ON ExpectationsView  
 (
    ExpectationName Language 1033,   
    ParentName Language 1033
 )   
  KEY INDEX PK_ExpectationsView 
      ON fts_catalog;
      WITH (CHANGE_TRACKING = AUTO)
GO

一旦包含相关列的 Full-Text 索引存在，您就可以在查询中使用 FREETEXT 或 CONTAINS：

SELECT ExpectationId, ExpectationName, ParentName FROM ExpectationsView
    WHERE FREETEXT(ExpectationName, @Keyword) OR FREETEXT(ParentName, @Keyword)

请注意，上面的代码是我凭空提供的，因为我没有适用于您的情况的数据模式，因此无法尝试运行。但是，它应该让您大致了解如何进行。 HTH.

SQL 服务器对具有别名的列进行全文搜索

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