擅长:python、mysql、java
<p>该列中有空值。当您要求降序时,空值将首先出现:</p>
<pre><code>select *
from (values (1), (null)) s(a)
order by a desc;
a
-
1
(2 rows)
</code></pre>
<p>如果你想保留空值,那么告诉它最后一个命令是空的</p>
^{pr2}$
<p>或者过滤掉空值</p>
<pre><code>select *
from (values (1), (null)) s(a)
where a is not null
order by a desc;
a
-
1
(1 row)
</code></pre>