MySQL表连接取决于条件

Question

我有四个这样的表： 表1：考试

-----------+--------------+---------
examID     |    examName  | session |
-----------+--------------+---------

表2：课程

-----------+--------------+---------
courseID   |     title    |  credit |
-----------+--------------+---------

表3：审查员

-------------+----------+-------------+------------+--------+
examinerID   |  examID  |  teacherID  |  courseID  |   part |
-------------+----------+-------------+------------+--------+
   1         |    1     |   3         |    5       | A or B |
-------------+----------+-------------+------------+--------+

表4：标记

---------+--------------+-------------+-----------+------
markID   |  examinerID  |  studentID  |  courseID | mark |
---------+--------------+-------------+-----------+------

我想对这些表运行一些查询，以便它根据examID生成php数组的课程表格，如下所示： -

$marks['courseID'] = array(
          'course'     => array(),//array of course details 
          'part_a_mark'=> array(),// array of marks of part A of that courseID 
          'part_B_mark'=> array(),// array of marks of part B of that courseID 
     );

Answer 1

使用SQL语句无法直接获得预期的输出。您需要在php循环语句中处理查询结果，然后遍历结果来形成数组。