Day06 operation -- addition, deletion, modification and query

1. Check the name and average score of each student

select name,avg(score) from stu group by name;

2. Check the names of students who failed in the exam

select distinct name from stu where score<60;

 3. Query the top three data with the highest scores

select * from stu order by score desc limit 0,3;

 

4. Add a new one rose My math score is 50 Minute data

insert into stu value(8,'rose',50,' mathematics ');

 

5. modify jack My math score is 85

update stu set score=85 where name='jack' and sk=' mathematics ';

 

6. Delete susanla Biological performance data

delete from stu where name='susanla' and sk=' biological ';

7. The query name contains c The data of

select * from stu where name like '%c%';