如何仅从日期字段返回最大年份的SQL行？

Question

所以我的数据库中有多个字段，其中之一是date 。 date字段是date数据类型，我只需要返回date字段中year最大的那些值。

到目前为止，我已经做到了：

$files = mysql_query("SELECT * FROM files WHERE unpublish=0 AND year(date) ORDER BY files.date DESC");

现在显然还不够，我该如何强制它将year(date)为仅返回最大值？

Answer 1

SELECT * FROM files 
WHERE unpublish=0 
AND year(date)=(SELECT MAX(YEAR(date)) FROM files) 
ORDER BY files.date DESC

Answer 2

尝试这个：

SELECT * FROM files 
WHERE unpublish=0 
and year(date)=(SELECT MAX(YEAR(date) FROM files)
ORDER BY files.date DESC

所以就像

$files = mysql_query("SELECT * FROM files 
    WHERE unpublish=0 
    and year(date)=(SELECT MAX(YEAR(date) FROM files)
    ORDER BY files.date DESC");

Answer 3

另一种选择是这样写：

$files = mysql_query("SELECT * FROM files
                      WHERE unpublish=0
                      AND date=(
                          SELECT YEAR(date)
                          FROM files
                          ORDER BY date DESC
                          LIMIT 1)
                      ORDER BY files.date DESC");

或者您可能想从SELECT命令中选择最长日期，例如：

$files = mysql_query("SELECT col1, col2, col3, max(YEAR(date)) AS date
                      FROM files
                      WHERE unpublish=0
                      ORDER BY files.date DESC");

其中col1，col2，col3是手动选择的列。