Question

在sqlite上，我有桌子

papers: rero_id, doi, year
writtenby: rero_id, authorid, instid
authors: author_id, name, firstname
inst: inst_id, name, see_id

inst是院校列表：大学等。书面形式的每一行都给出了一篇论文，一位作者，该作者当时所隶属的机构。可以有一个以上的机构，并且对每个机构重复一对夫妇的文件。对于给定的作者，我想要一份清单和他与之共同撰写论文的机构的数量。对于我尝试过的列表

SELECT  inst.name as loc
FROM (
(authors INNER JOIN writtenby ON authors.authorid = 
      writtenby.authorid) 
      INNER JOIN writtenby AS writtenby_1 ON writtenby.rero_id = 
       writtenby_1.rero_id

 ) 

 INNER JOIN authors AS auth_1 ON writtenby_1.authorid = 
 auth_1.authorid
 inner join inst on  writtenby_1.instid = inst.inst_id 

 WHERE (authors.name) ="Doe" AND (authors.firstname)= "Joe"
 ORDER BY loc

我得到的列表似乎还可以。

现在，我想重新组合这些机构名称并进行计数。我尝试过

 SELECT  inst.name, count(inst.name)
 FROM (
    (authors INNER JOIN writtenby ON authors.authorid = 
     writtenby.authorid) 
     INNER JOIN writtenby AS writtenby_1 ON writtenby.rero_id = 
     writtenby_1.rero_id

 ) 

 INNER JOIN authors AS auth_1 ON writtenby_1.authorid = 
 auth_1.authorid
 inner join inst on  writtenby_1.instid = inst.inst_id 
 GROUP BY inst.name
 HAVING (authors.name) ="Doe" AND (authors.firstname)= "John"

我只有三行，没有第一条查询中列出的机构。感谢您纠正我！

François

Answer 1

尝试使用where而不是

 SELECT  inst.name, count(inst.name)
 FROM (
    (authors INNER JOIN writtenby ON authors.authorid = 
     writtenby.authorid) 
     INNER JOIN writtenby AS writtenby_1 ON writtenby.rero_id = 
     writtenby_1.rero_id

 ) 

 INNER JOIN authors AS auth_1 ON writtenby_1.authorid = 
 auth_1.authorid
 inner join inst on  writtenby_1.instid = inst.inst_id 
 where authors.name ='Doe' AND authors.firstname= 'John' 
 GROUP BY inst.name

Answer 2

我明白了，

SELECT inst.name as loc, count(*) as c
FROM (
(authors INNER JOIN writtenby ON authors.authorid = writtenby.authorid) 
INNER JOIN writtenby AS writtenby_1 ON writtenby.rero_id = 
writtenby_1.rero_id
inner join inst on  writtenby_1.instid = inst.inst_id 
) 
INNER JOIN authors AS auth_1 ON writtenby_1.authorid = auth_1.authorid
WHERE (authors.name) ="Doe" AND (authors.firstname)= "John"
GROUP BY inst.name
ORDER BY c DESC

我仍然可以使用where子句，这与拥有...不同感谢fa6在下面给出了答案 F。

sqlite：count和group by子句未提供预期的结果

2 个答案: