SQL Server 对具有别名的列进行全文搜索

Question

我正在使用全文搜索，它在表的直接列上工作正常，但在派生/别名列上工作正常。

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

ExpectationName、OrganizationName、BeneficiaryName、TeamName 的所有这些列都被全文索引。

如何使它适用于ParentName 列？

Answer 1

您需要首先根据您的查询创建一个VIEW，然后向其中添加一个全文索引，其中将包括ParentName 列。如果没有对正在搜索的列的全文索引，FREETEXT 和 CONTAINS 都将不起作用。

类似的东西应该可以帮助你：

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  

一旦包含相关列的全文索引在那里，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，上面的代码是我在脑海中提供的，因为我没有适用于您的案例的数据架构，因此无法尝试运行它。但是，它应该为您提供有关如何进行的总体思路。 HTH。