mysql - MySQL LEFT OUTER JOIN与LIMIT？

这是我的查询

SELECT `t`.`id` AS `t0_c0`
 , `news`.`id` AS `t2_c0`
 , `news`.`title` AS `t2_c1`
 , `news`.`url` AS `t2_c2`
 , `news`.`date` AS `t2_c3`
 , `news`.`hash` AS `t2_c4`
 , `news`.`list_id` AS `t2_c5`
FROM
`words` `t`
LEFT OUTER JOIN `words_news` `news_news`
ON (`t`.`id` = `news_news`.`word_id`)
LEFT OUTER JOIN `news` `news`
ON (`news`.`id` = `news_news`.`news_id`)
WHERE
  (`t`.`id` IN (8229, 8574, 7901))

并且我只需要从news表中选择5条新闻，但是不知道如何，该如何编写查询？

最佳答案

尝试这个：

    SELECT `t`.`id` AS `t0_c0`
     , `news`.`id` AS `t2_c0`
     , `news`.`title` AS `t2_c1`
     , `news`.`url` AS `t2_c2`
     , `news`.`date` AS `t2_c3`
     , `news`.`hash` AS `t2_c4`
     , `news`.`list_id` AS `t2_c5`
FROM
  `words` `t`
LEFT OUTER JOIN `words_news` `news_news`
ON (`t`.`id` = `news_news`.`word_id`)
LEFT OUTER JOIN (SELECT * FROM `news` LIMIT 5) `news`
ON (`news`.`id` = `news_news`.`news_id`)
WHERE
  (`t`.`id` IN (8229, 8574, 7901));

要么

SELECT `t`.`id` AS `t0_c0`
 , `news`.`id` AS `t2_c0`
 , `news`.`title` AS `t2_c1`
 , `news`.`url` AS `t2_c2`
 , `news`.`date` AS `t2_c3`
 , `news`.`hash` AS `t2_c4`
 , `news`.`list_id` AS `t2_c5`
FROM
  `words` `t`
LEFT OUTER JOIN `words_news` `news_news`
ON (`t`.`id` = `news_news`.`word_id`)
LEFT OUTER JOIN `news` `news`
ON (`news`.`id` = `news_news`.`news_id`)
JOIN (SELECT @var_ctr := 0) a
WHERE IF(`news`.`id` IS NOT NULL, @var_ctr := @var_ctr + 1, @var_ctr) <= 5
      AND (`t`.`id` IN (8229, 8574, 7901));

关于mysql - MySQL LEFT OUTER JOIN与LIMIT？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/11985469/