c# - 全文搜索 - 有没有办法获取导致查询行的列名

Question

在 ms sql 2012 服务器中，我在几列上有一个全文搜索索引。
我使用 FREETEXTTABLE 或 CONTAINSTABLE 进行查询，如果搜索文本出现在多列而不是其他列，我的反应应该不同。
有没有办法区分或接收结果出现的列名？
谢谢。

Answer 1

我假设您调用 FREETEXTTABLE/CONTAINSTABLE 时可以*选择在所有列中进行搜索。相反，请尝试进行多次调用，每列一个。您可以在 1 个查询中执行此操作，也可以根据具体情况作为单独的查询执行此操作。

例如（1-查询方法）：

SELECT
   Case
      When (MatchesColumn1or2.[KEY] is not null) Then 'Matches Column 1 or 2'
      When (MatchesColumn3.[KEY] is not null) Then 'Matches Column 3'
   End
FROM
   FREETEXTTABLE(MyTable, (Column1, Column2), 'cat AND dog') as MatchesColumn1or2
full outer join
   FREETEXTTABLE(MyTable, Column3, 'cat AND dog') as MatchesColumn3
   on (MatchesColumn1or2.[KEY] = MatchesColumn3.[KEY])

这是一个示例，如果您想保留原始排名值，但请注意增加的性能损失：

SELECT
   MatchAllColumns.[RANK],
   Case
      When (MatchesColumn1or2.[KEY] is not null) Then 'Matches Column 1 or 2'
      When (MatchesColumn3.[KEY] is not null) Then 'Matches Column 3'
   End
FROM
   FREETEXTTABLE(MyTable, *, 'cat AND dog') as MatchAllColumns
left join
   FREETEXTTABLE(MyTable, (Column1, Column2), 'cat AND dog') as MatchesColumn1or2
   on (MatchAllColumns.[KEY] = MatchesColumn1or2.[KEY])
left join
   FREETEXTTABLE(MyTable, Column3, 'cat AND dog') as MatchesColumn3
   on (MatchAllColumns.[KEY] = MatchesColumn3.[KEY])