sql - 选择按列总和排序的两个查询的交集

Question

我有如下三个表:

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

Words 表包含所有文档中出现的所有单词，word_document 将单词与文档以及该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词，并只返回两个词都按文档中两个词的计数之和排序的文档。

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 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

我成功地使用了intersect，但它没有返回计数总和，也没有顺序。

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