使用结果中的值来避免双重MySQL查询

Question

如果“内容”字段包含特定短语，则需要获取“标题”字段。有了标题，我可以做实际的查询来获取帖子。

- 伪码 -

$query1 ='SELECT `title` FROM `posts` WHERE `content` CONTAINS 'matchtest' 
ORDER BY `id` ASC, LIMIT 1'; 
$titlefromquery1; 

$query2 = 'SELECT * FROM `posts` WHERE `title` = 'Reply to: ' . $titlefromquery1; 
$repliesfromquery2; 

的答复没有短语幸运匹配“titles”永远是“Reply to: $title”这就是为什么这两个查询都需要它似乎

是否有条件或其他方式避免双重查询？

Answer 1

SELECT * FROM posts 
WHERE title= 
concat_ws('Reply to: ', 
(SELECT title FROM posts WHERE <put_your_condition> ORDER BY id ASC LIMIT 1)) 

Answer 2

您可以使用临时变量来实现这一目标：

SELECT @title:=`title` FROM `posts` WHERE `content` CONTAINS 'matchtest' ORDER BY `id` ASC, LIMIT 1; 

SELECT * FROM `posts` WHERE `title` = CONCAT('Reply to: ' , @title);