如何在mysql中實現join

Question

伙計們，有人可以告訴我如何在聯接中實現以下查詢，與以下查詢相比，該查詢具有更高的性能

SELECT *, count(*) c FROM question_ans_word where answer_id in
  (select answer_id from question_ans_word where keywords_id in
     (SELECT id FROM uniqueword where word like "minimum")
  )
group by answer_id;

Answer 1

以下是您如何使用聯接執行此操作。 我是否能說出它是否會更好：

select a.*, count(*) c
  from question_ans_word a
  inner join question_ans_word qw
    on qw.answer_id = a.answer_id
  inner join uniqueword u
    on u.id = qw.keywords_id
  where u.word like "minimum"
  group by a.answer_id

祝你好運。

Answer 2

根據我的理解，看起來像這樣...

From question_ans_word qaw
JOIN uniqueword uw on qaw.keywords_id = uw.id and word like "minimum"

Answer 3

嘗試這個，

select *, count(*) c from question_ans_word qw INNER JOIN uniqueword uw ON uw.id = qw.keywords_id WHERE uw.word like "minimum" group by answer_id