Question

我有以下表格结构：

id      |name     |date
1        a         2012-01-01
2        a         2011-01-01
3        a         2010-01-01
4        a         2014-01-01
5        a         2011-01-01

我希望按日期执行选择顺序（desc），然后从结果中选择前3行，条件是id = 1.所以查询的第二部分将是＆＃34;给我从id等于1＆＃34;

的行开始的前3行

修改在第一个＆＃34;部分＆＃34;结果将是： SELECT id, name, date FROM table ORDER BY date DESC

id      |name     |date
4        a         2014-01-01
1        a         2012-01-01
2        a         2011-01-01
5        a         2011-01-01
3        a         2010-01-01

在第二部分之后它应该是这样的（所以在id为1的行之后的前3个）：

id      |name     |date
2        a         2011-01-01
5        a         2011-01-01
3        a         2010-01-01

我不知道如何解决它，请帮助我。

修改这是我想重写的具体代码：

SELECT `id`, `questions`.`userid`, `categories`.`name`, `user`.`username`, `title`,
   `details`, `date` FROM `questions`
 LEFT JOIN `user`
   ON `questions`.`userid` = `user`.`userid`
 LEFT JOIN `categories`
   ON `questions`.`categoryid` = `categories`.`categoryid`
ORDER BY `date` DESC LIMIT 10

Answer 1

这并不漂亮，因为MySQL不支持row_number()或公用表表达式，但它应该有效。基本上，获取按日期排序的行号，然后选择行号大于任意值的行号（在本例中为1）。最后使用limit选择所需的记录数。

SELECT id, name, mydate 
FROM (
  SELECT id, name, mydate, @rn:=@rn+1 rn
  FROM mytable, (select @rn:=0) t 
  ORDER BY mydate DESC
) t2
WHERE rn > (
  select rn
  from (
    SELECT id, name, mydate, @rn:=@rn+1 rn
    FROM mytable, (select @rn:=0) t 
    ORDER BY mydate DESC
  ) t2
  where id = 1
)
LIMIT 3

SQL Fiddle Demo

Answer 2

这是你想要做的......如果找到第一个id等于4然后选择那个。然后限制偏移量以转到下一行并拉出3

SELECT id, name, m_date from(
SELECT id, name, m_date, @a := id, if(@a = 4, @b := 1, @b) AS join_id
FROM test
join(SELECT @a := 0, @b := 0) t
ORDER BY m_date DESC
  ) AS tt
WHERE join_id = 1
LIMIT 1,3

SELECT temp.`id`, temp.`userid`, `categories`.`name`, `user`.`username`, temp.`title`,
   temp.`details`, temp.`date` FROM (
SELECT `id`, `categoryid`, `details`, `title`, `userid`, `date`, @a := id, if(@a = 11, @b := 1, @b) AS join_id
FROM `questions`
join(SELECT @a := 0, @b := 0) t
ORDER BY `date` DESC
) as temp
 LEFT JOIN `user`
   ON temp.`userid` = `user`.`userid`
 LEFT JOIN `categories`
   ON temp.`categoryid` = `categories`.`categoryid`
WHERE join_id = 1
LIMIT 1,10;

SEE FIDDLE需要澄清

Answer 3

SELECT   *
FROM     table
WHERE    date < (SELECT date FROM table WHERE id = 1)
ORDER BY date DESC
LIMIT    3

从定义的值中选择select语句

3 个答案: