SELECT A.student_id,sw,wl from (SELECT student_id,num as sw from score LEFT JOIN course on score.course_id=course.cid where course.cname='生物')as A LEFT JOIN (SELECT student_id,num as wl from score LEFT JOIN course on score.course_id=course.cid where course.cname='物理')as B on A.student_id =B.student_id where sw > if (ISNULL(wl),0,wl);
自己写了一段
SELECT A.student_id,sw,wl from (SELECT student_id,num as sw from score where course_id=(SELECT cid from course WHERE cname='生物')) as A LEFT JOIN (SELECT student_id,num as wl from score where course_id=(SELECT cid from course WHERE cname='物理')) as B on A.student_id=B.student_id where sw > if (ISNULL(wl),0,wl)
select student_id,avg(num) from score group by student_id having avg(num) > 60
4、查询所有同学的学号、姓名、选课数、总成绩
select score.student_id,student.sname,count(score.student_id),sum(score.num) from score left join student on score.student_id=student.sid group by score.student_id
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Strapi offers a lot of flexibility. Whether you want to go fast and quickly see the final result, or would rather dive deeper into the product, we got you covered. For this tutorial, we'll go for the DIY approach and build a project and data structure from scratch.
☑️ Prerequisites
Before installing Strapi, the following requirements must be installed on your computer:
Node.js
: Only
Active LTS or Maintenance LTS versions
are supported (currently
v18
and
v20
). Odd-number releases of Node, known as "current" versions of Node.js, are not supported (e.g. v19, v21).