php - 如何在一个mysql表中按特定年份过滤特定类(class)？

我正在一个网站上工作，该网站要求我仅在一张表中按年显示特定课程。

这是我桌子上的一些细节：

表学生

stdID，stdCourseDesc，accessDate

12211，飞机维修许可计划？ EASA第66部分，2018-3-6

12212，飞机维修许可计划？ EASA第66部分，2015-8-6

12213，飞机维修技术（制造）文凭，2017-3-1

12214，工商管理硕士（企业家），2018-1-16

12215，飞机维修许可计划？ EASA第66部分，2015-10-1

12216，飞机维修许可计划？ EASA第66部分，2016-12-10

12217，哲学博士（制造），2016-5-14

在此之前，我只能进行编码，但是当然，它仅显示课程。

SELECT CONCAT(`stdCourseDesc`, ', ', `accessDate`) AS byYear FROM student WHERE `stdCourseDesc` = 'Aircraft Maintenance License Program ? EASA Part 66'

我试过了但是失败了。

SELECT CONCAT(stdCourseDesc, ', ', accessDate) AS byYear FROM student where `stdCourseDesc` = 'Aircraft Maintenance License Program ? EASA Part 66', YEAR(`accessDate`)=2015

我将使用此代码显示输出

$conn = new mysqli ('localhost', 'root', '', 'dashboard');

$aircraftyear2015 = $conn ->query ("SELECT CONCAT(`stdCourseDesc`, ', ',
`accessDate`) AS byYear FROM student WHERE `stdCourseDesc` = 'Aircraft
Maintenance License Program ? EASA Part 66'");
$aircraftyear2016 = $conn ->query ("SELECT CONCAT(`stdCourseDesc`, ', ',
`accessDate`) AS byYear FROM student WHERE `stdCourseDesc` = 'Aircraft
Maintenance License Program ? EASA Part 66'");
$aircraftyear2017 = $conn ->query ("SELECT CONCAT(`stdCourseDesc`, ', ',
`accessDate`) AS byYear FROM student WHERE `stdCourseDesc` = 'Aircraft
Maintenance License Program ? EASA Part 66'");
$aircraftyear2018 = $conn ->query ("SELECT CONCAT(`stdCourseDesc`, ', ',
`accessDate`) AS byYear FROM student WHERE `stdCourseDesc` = 'Aircraft
Maintenance License Program ? EASA Part 66'");

$tot_aircraftyear2015 = mysqli_num_rows($aircraftyear2016);
$tot_aircraftyear2016 = mysqli_num_rows($aircraftyear2017);
$tot_aircraftyear2017 = mysqli_num_rows($aircraftyear2016);
$tot_aircraftyear2018 = mysqli_num_rows($aircraftyear2017);

<?php echo $tot_aircraftyear2015; ?>
<?php echo $tot_aircraftyear2016; ?>
<?php echo $tot_aircraftyear2017; ?>
<?php echo $tot_aircraftyear2018; ?>

我要如何在一张mysql表中按特定年份过滤特定课程？

我的代码可以用于显示数据吗？
先感谢您

最佳答案

看起来可能是语法问题，请尝试以下操作：

SELECT CONCAT(stdCourseDesc, ', ', accessDate) AS byYear
FROM student
WHERE  `stdCourseDesc` = 'Aircraft Maintenance License Program ? EASA Part 66'
  AND YEAR(`accessDate`) = '2015'

关于php - 如何在一个mysql表中按特定年份过滤特定类(class)？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/49891194/