Database operation skills 6

1. establish test database

2.  stay test Create in the database student surface

3.  towards student Add records to the table

4. Use sql Statement to query the table id,name, and address All the contents of the field

5. Use sql Statement to query all students in the table id,name,score

6. change useremail The data type of the field is varchar(50)

7.  Add a field to the table , The field name is “pingjia”, Field type is varchar(20)

8. Change the score of the classmate whose name is Zhang San to 92

 

9. If 80 It's a passing line , Find out the details of all the students who failed

 

10. Name is “ Xiaohong ” Students' scores are on the original basis +20

 

11. Use keywords in, Inquire about id The value is 1 or 5 or 7 Basic information of students

 

12. Inquire about id Values in 4 to 9 Basic information of all students

 

13. The query name is Xiaohong and the score is greater than 60 Basic information of students

 

14. The query name is Xiao Hong or the score is greater than 90 Basic information of students

 

15. Inquire about score The field value is NULL Basic information of students

 

16. Inquire about name Not Zhang San's classmate id,name, and score

17. Ascending by address , The grades are in descending order

 

 

18. De duplicate the city