mySQL投票系统选择

我有一个投票系统，表格如下：

answers
-----------
int id
text content

results
-----------
int id
int answers_id

SELECT 
count(results.answers_id), answers.content
from answers
left outer join results
on answers.id = results.answers_id
group by results.answers_id

我想要一个选择，这样即使没有votesresults，我也可以看到答案和响应的数量。 我试过这样的方法：

answers
-----------
int id
text content

results
-----------
int id
int answers_id

SELECT 
count(results.answers_id), answers.content
from answers
left outer join results
on answers.id = results.answers_id
group by results.answers_id

但是它不会得到0个votesresults的答案。

试试看

SELECT
count(result.answers_id) as acount, answers.content
from answers
left inner join results
on answers.id = acount

使用子查询

SELECT a.*,
   ( SELECT COUNT(*)
     FROM results r
     WHERE a.id = r.answers_id
   )
FROM answers a

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试试这个，根据答案的Id分组

SELECT 
COUNT(results.answers_id) AS NumberOfAnswers, answers.content
from answers
left join results
on answers.id = results.answers_id
group by answers.id

要确保没有两行内容相同，请按answers.content分组

使用Ifnull，并在您的分组中按语句将其更改为answers.content

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我认为解决办法是使用

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这应该可以做到：

SELECT count(results.answer_id), answers.content
from answers left outer join results on answers.id = results.answer_id
group by answers.content;

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我不认为这会起作用，如果在select子句中使用了聚合函数，不应该按子句添加group by吗？COUNTcolumn不计算NULL不投票。使用count*计算所有-包括null！

SELECT count(results.answer_id), answers.content
from answers left outer join results on answers.id = results.answer_id
group by answers.content;