SQL statement exercise

One 、

1. establish test database

 2. stay test Create in the database student surface , The table structure is shown in the following figure (id Set as primary key self growth )

 

 

3. towards student Add records to the table as shown in the following figure

 

 4. Use sql Statement to query all contents in the table

5.  Use sql Statement to query all score>70 Of my classmates id,name,score

6.  change name 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 88

       

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

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

11.  Inquire about id Values in 5 to 8 Basic information of all students

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

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

Two 、 

1. establish test database

2. stay test Create in the database emp surface , The table structure is shown in the following figure (id Set as primary key self growth )

 

 3. towards emp Add records to the table as shown in the following figure

 

4.  Look up everything in the table

 

5. The name in the query table is all the message records of Zhang San

 

6. The name in the query table is the name of all employees consisting of three words ename,job,sal The corresponding information of the field

 

7. In the query table empno Fields from 1004 to 1008 Records of all employees

 

 

8. Query all in the table job All the information of the employee whose field is clerk and whose name is Huang Gai

 

9. Query table in 2001 Information of employees who have been employed since

 

 

10. The bonus in the query table （COMM） yes NULL Employee information

3、 ... and 、 

1. establish test database

 

2. stay test Create in the database student surface , The table structure is shown in the following figure (id Set as primary key self growth )

 

 3. towards student Add records to the table as shown in the following figure

 

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

Four 、

1. establish db_test database

 

2. stay test Create in the database yuangong surface , The table structure is shown in the following figure (id Set as primary key self growth )

 

 

 3. towards yuangong Add records to the table as shown in the following figure

 

 4. Look up everything in the table

 

5. Change the table name to ”emp”

 

6. modify ename The type of field is varchar(40)

 

7. Delete... From the table empno yes 1014 also ename It's Huang Gai's employee information

 

8. In the query table empno The value of the field is 1007,1009 or 1011 All records of employees

 

9. Query all in the table job All the information of the employee whose field is clerk and whose name is Zhang San

 

10. Query table in 2001 Information of employees who have been employed since

5、 ... and 、

 

 

1： Check the name and average score of each student

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

3： Query the top three data with the highest scores

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

5： modify jack My math score is 85

6： Delete susanla Biological performance data

7： The query name contains c The data of