Question

我有三张表如下：

documents (id, content) 
words (id, word) 
word_document (word_id, document_id, count)

单词表包含所有文档中出现的所有单词，word_document将单词与文档和文档中该单词的计数相关联。

我想编写一个查询来搜索两个单词，并且只返回两个单词的文档，这两个单词的排序方式是文档中两个单词的总数。

例如

DocA: green apple is not blue
DocB: blue apple is blue
DocC: red apple is red

现在搜索 apple 和 blue 会返回：

DocA, 3
DocB, 2

因为...

DocA contains both words and 3 of them
DocB contains both words and 2 of them
DocC only contains one word

我成功使用了 intersect ，但它没有返回计数总和而没有订单。

Answer 1

我认为应该这样做：

select a.document_id, a.count + b.count
from 
(
 select document_id, count
 from word_document
 where word_id = 'apple'
 group by document_id
) a 
INNER JOIN 
(
 select document_id, count
 from word_document
 where word_id = 'blue'
 group by document_id
) b 
ON a.document_id = b.document_id
ORDER BY a.count + b.count

Answer 2

对于那些想要这个的人来说，这只会起作用：

select wd.document_id, (wd.count + d.count) as tcount from word_document as wd
join words as w on w.id = wd.word_id
join
(select document_id, count from word_document 
join words on words.id = word_document.word_id
where words.word = "apple") d on d.document_id=wd.document_id
where w.word = "blue" order by tcount desc

您可以从内部查询创建临时表并在其上执行外部。它可以递归地完成更多的单词。

选择按列总和排序的两个查询的交集

2 个答案: