柳州做网站有kv,东莞商贸公司寮步网站建设价格,盐城做网站哪家好,配置安装环境 wordpress 阿里云建完库与建完表后后:1.分别查询student表和score表的所有记录student表#xff1a;score表:2.查询student表的第2条到5条记录SELECT * FROM student LIMIT 1,4;3.从student表中查询计算机系和英语系的学生的信息SELECT * FROM student- WHERE department IN (计算机系, 英…建完库与建完表后后:1.分别查询student表和score表的所有记录 student表score表:2.查询student表的第2条到5条记录SELECT * FROM student LIMIT 1,4;3.从student表中查询计算机系和英语系的学生的信息SELECT * FROM student- WHERE department IN (计算机系, 英语系);4.从student表中查询年龄小于22岁的学生信息select * from student- where 2025 - birth 22 ;5.从student表中查询每个院系有多少人select department, count(*) as student_count- from student- group by department;6.从score表中查询每个科目的最高分select c_name,max(grade) as max_grade- from score- group by c_name;7.查询李广昌的考试科目(c name)和考试成绩(grade)select s.c_name , s.grade- from student st- join score s on st.id s.stu_id- where st.name 李广昌;8.用连接的方式查询所有学生的信息和考试信息select st.*,s.c_name,s.grade- from student st- left join score s on st.id s.stu_id;9.计算每个学生的总成绩select stu_id,sum(grade) as total_grade- from score- group by stu_id;10.计算每个考试科目的平均成绩select c_name,avg(grade) as avg_grade- from score- group by c_name;11.查询计算机成绩低于95的学生信息select st.*- from student st- join score s on st.id s.stu_id- where s.c_name 计算机 AND s.grade 95- ;12,将计算机考试成绩按丛高到低进行排序select * from score- where c_name 计算机- order by grade desc;13.从student表和score表中查询出学生的学号然后合并查询结果select id as student_id- from student- union- select stu_id from score;14.查询姓张或者姓王的同学的姓名、院系和考试科目及成绩select st.name , st.department , s.c_name , s.grade- from student st- left join score s on st.id s.stu_id- where st.name like 张% or st.name like 王%;15.查询都是湖南的学生的姓名、年龄、院系和考试科目及成绩 select st.name , 2025 - st.birth as age ,st.department , s.c_name , s.grade- from student st- left join score s on st.id s.stu_id- where st.address like %湖南省%;
