查询学号为“10002”的学生的所有成绩，结果需包含学号、姓名、所在系别、课程号、课程名及对应成绩。 （2） 查询每位学生成绩大于85的课程，结果需包含学号、姓名、所在系别

在数据库查询中，要获取特定学生的信息和满足条件的成绩，通常会涉及到两个SQL查询：

1. **查询学号为“10002”的学生所有成绩**

   SELECT students.id AS 学号, students.name AS 姓名, departments.department_name AS 所在系别,
          courses.course_code AS 课程号, courses.course_name AS 课程名, grades.score AS 成绩
   FROM students
   JOIN student_departments ON students.id = student_departments.student_id
   JOIN departments ON student_departments.department_id = departments.id
   JOIN courses ON courses.id = students.courses_taken_id
   WHERE students.id = '10002';

2. **查询每位学生成绩大于85的课程信息**

   SELECT students.id AS 学号, students.name AS 姓名, departments.department_name AS 所在系别
   FROM students
   JOIN student_departments ON students.id = student_departments.student_id
   JOIN departments ON student_departments.department_id = departments.id
   WHERE students.id IN (
       SELECT student_id
       FROM grades
       WHERE score > 85
   );