mysql - 从虚拟列中获取最高值

Question

SELECT *, REPLACE(number_option, 'Issue ', '') AS new_number_option FROM
jgl_article WHERE status = 1 AND topic = 'Current Issues' ORDER BY id ASC

new_number_option列返回：

1

1

1

2

2

3

3

我想从new_number_option列中获取最高值。这里3是最高值。所以，我想获得包含最高价值的记录。我在上面的查询中尝试了HAVING MAX（new_number_option）。但是，它不会起作用。

Answer 1

请尝试CAST，因为您的列类型为string

CAST(new_number_option as SIGNED)

使用

MAX( CAST(REPLACE(number_option, 'Issue ', '') AS UNSIGNED) )

Answer 2

SELECT JA.*
  FROM
jgl_article JA INNER JOIN
     (SELECT MAX( CAST(REPLACE(number_option, 'Issue ', '') AS UNSIGNED) ) AS MAX_number_option FROM
      jgl_article) T
              ON CAST(TRIM(JA.number_option) as UNSIGNED) = T.MAX_number_option
WHERE JA.status = 1 AND JA.topic = 'Current Issues'

这将有效

希望这会有所帮助..