全文检索备忘

 全文检索查询

在一个表中创建了全文索引后 才可以对表中的数据进行全文检索Full-Text Catalogs 进行全文检索需要在 SELECT 命令的 WHERE 字句中使用两个 Transact-SQL 谓词 CONTAINS 和 FRETEXT

1、CONTAINS
CONTAINS 谓词的语法如下
CONTAINS ( { column_name | * } , '< contains_search_condition >'   )
< contains_search_condition > ::=
 { < simple_term >
        | < prefix_term >
        | < generation_term >
        | < proximity_term >
        | < weighted_term >
        }
        | { ( < contains_search_condition > )
        { AND | AND NOT | OR } < contains_search_condition > [ ...n ]
        }

select *
from firms
where contains(f_intro, ' " science and technology " or " information " ')

select *
from firms
where contains(f_name, ' "infor*" ')

select *
from firms
where contains(f_intro, ' "software" NEAR "company" ')

select *
from firms
where contains(f_intro, ' formsof (inflectional, limit) ')      /*查找limit及其变体单词中，如limits*/

2、FREETEXT
FREETEXT 谓词的语法如下
FREETEXT ( { column_name | * } , 'freetext_string' )
FREETEXT 谓词的含义与 CONTAINS 类似 但它比 CONTAINS 谓词功能弱 只支持纯文字的搜索 即 freetext_string 只能为单词 短语或句子 而不能使用逻辑表达式等
例 查找公司名称中含有 Management Information System 短语的公司信息
select *
from firms
where contains(firm_name, ‘Management Information System’)
例 查找公司介绍中含有 It’s an excellent company. 句子的公司信息
select *
from firms
where contains(firm_intro, ‘It’s an excellent company.’)