MySQL 带子表达式的布尔全文搜索

Question

我想在 MySQL 中编写布尔全文搜索查询。但我希望按以下顺序获得结果：

Exact Matches > Including all the words > Including some of the words

（>表示更高。）

通过以下查询，我得到更高的精确匹配：

SELECT *, MATCH(name,description,address) 
AGAINST('>("word1 word2 word3") <(word1 word2 word3)' IN BOOLEAN MODE) 
AS score FROM samples WHERE MATCH(name,description,address) 
AGAINST('>("word1 word2 word3") <(word1 word2 word3)' IN BOOLEAN MODE) ORDER BY score DESC

通过以下查询，我得到的文档包含的所有词都高于包含查询的某些部分的词：

SELECT *, MATCH(name,description,address) 
AGAINST('>(+word1 +word2 +word3) <(word1 word2 word3)' IN BOOLEAN MODE) 
AS score FROM samples WHERE MATCH(name,description,address) 
AGAINST('>(+word1 +word2 +word3) <(word1 word2 word3)' IN BOOLEAN MODE) ORDER BY score DESC

但我想合并这两个查询。这是迄今为止我得到的最好结果，但我没有得到我想要的结果。

SELECT *, MATCH(name,description,address) 
AGAINST('>("word1 word2 word3") <(>(+word1 +word2 +word3) <(word1 word2 word3))' IN BOOLEAN MODE) 
AS score FROM samples WHERE MATCH(name,description,address) 
AGAINST('>("word1 word2 word3") <(>(+word1 +word2 +word3) <(word1 word2 word3))' IN BOOLEAN MODE) 
ORDER BY score DESC

有没有不用 UNION 的方法？

Answer 1

( SELECT *,
         1 AS sort_order,       -- top priority to exact match
         1.0 AS extra_ordering
      ... WHERE txt = 'aaaa bbbb cccc' )
UNION ALL
( SELECT *,
         2 AS sort_order,      -- next to all words exist
         MATCH(txt) AGAINST("+aaaa +bbbb +cccc" IN BOOLEAN MODE)
      ... WHERE MATCH(txt) AGAINST("+aaaa +bbbb +cccc" IN BOOLEAN MODE)
UNION ALL
( SELECT *,
         3 AS sort_order,      -- finally "any" words
         MATCH(txt) AGAINST("aaaa bbbb cccc" IN BOOLEAN MODE)
      ... WHERE MATCH(txt) AGAINST("aaaa bbbb cccc" IN BOOLEAN MODE)
ORDER BY sort_order ASC, extra_ordering DESC
LIMIT 1;  -- to get the 'best'

Answer 2

这行得通吗？

  SELECT *,
         MATCH (name,description,address) 
           AGAINST ('"word1 word2 word3"' IN BOOLEAN MODE) score_exact,
         MATCH (name,description,address) 
           AGAINST ('+word1 +word2 +word3' IN BOOLEAN MODE) score_all,
         MATCH (name,description,address) 
           AGAINST ('word1 word2 word3' IN BOOLEAN MODE) score_some
    FROM samples
   WHERE MATCH (name,description,address) 
           AGAINST ('word1 word2 word3' IN BOOLEAN MODE)
ORDER BY score_exact DESC, score_all DESC, score_some DESC

MySQL 带子表达式的布尔全文搜索

MySQL boolean full text search with subexpressions

mysql

database

full-text-search

information-retrieval