在 $query 中添加 COUNT 和 DISTINCT

Question

如何在下面的 $query 中添加 select COUNT 和 DISTINCT？如果您需要任何其他详细信息来解决此问题，请告诉我。感谢您的时间。

if(isset($_POST["intake_year"]))

{

 $query = "

 SELECT * FROM marketing_data

 WHERE intake_year = '".$_POST["intake_year"]."'

 ";

 $statement = $connect->prepare($query);

 $statement->execute();

 $result = $statement->fetchAll();

 foreach($result as $row)

 {

  $output[] = array(

   'semester'   => $row["semester"],

   'student_matric'  => floatval($row["count"])

  );

 }

 echo json_encode($output);

}

//SELECT count(student_matric) AS count, semester, intake_year FROM marketing_data GROUP BY intake_year - 此查询仅用于 COUNT student_matric

//SELECT DISTINCT semester FROM marketing_data ORDER BY semester DESC - 此查询仅针对 DISTINCT 学期

Answer 1

我想你正在寻找类似的东西 $query = " SELECT distinct semester , count(student_matric) as count FROM marketing_data WHERE intake_year = '".$_POST["intake_year"]."' Group by student_matric " ;