小编Mod*_*esi的帖子

我正在处理我的HTML任务.这是基本的CSS东西(外部样式表),我差不多完成了.一切都按照应有的方式运作,除了一部分,我无法弄清楚为什么.

</header>

     <article>
        <h2>About the Course</h2>
        <p>
           The Civil War and Reconstruction
           explores the causes and consequences of the American 
           Civil War, covering American history from 1840 through 1876 in
           great detail. My primary goal is to interpret the multiple 
           threads that run through this epic event and consider how these
           threads still engage the politics and culture of the 
           present day. In this course we will rely heavily on primary
           texts, interpreting the events of the day through the …

我想要获取 60 岁或以上人士的姓氏、出生日期和年龄。到目前为止，我就是这样做的：

Select *
FROM ( SELECT TIMESTAMPDIFF(YEAR,bdate,CURDATE()) AS age
FROM 
employee
) AS d
WHERE
age>=60

它可以工作，但是如果我输入 lname, bdate 而不是 * ，我会收到错误。“‘字段列表’中存在未知列‘lname’。” 我不太清楚如何获取姓氏和出生日期，并且不断收到相同的错误。