随笔分类 -  MySQL

摘要：有一个test数据库，里面有一张学员表student，有三个字段，calss,name,score，分别代表班级，姓名，成绩查询每个班级的几个人数和不及格人数，输出格式是 class，及格人数，不及格人数select class,(select count(*) from student where class="stu".class and score>=60) jige,(select count(*) from student where class="stu".class and score<60) bujigefrom studen 阅读全文