Question

Q2. Write SQL query for the following tables:
TI(rollno, stuname, age, city, branchcode)
T2(branchcode, branchname)
1. Find an average age of all students,
2. Change age of student to 20 to 22 whose rollno is 1
3. Delete student details whose age is 18.
4. Retrieve branch information in descending order.
5. List all names of all students who have age between 20 and 25.​

Answer 1

Answer:

1. select AVG(age) from T1

2. update T1 set age = 22 where rollno=1  

3. delete from T1 where age = 18  

4. select branchname from T2 order by desc  

5. select stuname from T1 where age between 20 and 25

Explanation:

1. Query type: Select column with apply a function,  

AVG() function is used to calculate the average of the age.  

2. Query type : Update the existing record with where condition

3. Query type: Delete the record with where condition

4. Query type: select with order by

5. Query type: Select with where condition