text: -- QUESTION 3
  /*
  STUDENT DATABASE
  class_(class_id, class_name, division, st_cnt)
  student(st_id, st_fname, st_lname, addr, phone, email, class_id)
  teacher(teacher_id, fname, lname, phone, subject)
  student_class(st_id, class_id, teacher_id)
  */
  
  -- 1)Create all the tables and insert data.
  
  -- 2)List all classes where strength is greater than 50
  
  -- 3)List the name of students of Lina teacher.
  
  -- 4)List the names of all the English teachers.
  
  -- 5)List the names of teachers who teach standard 9
  
  -- 6)Find out all the classes that are taught by Jaya teacher
  
  -- 7)List the names and details of all students in standard 10
  
  -- 8) List all the students whose first name is the same along with their student id
  
  -- 9)List the name of students whose name starts with 's'.
  
  
  
  -- QUESTION 4 - PROCEDURE
  /*
  BANK DATABASE
  branch(b_id, bname, city)
  customer(c_id, cname, city)
  deposit(acc_no, c_id, b_id, amount, date)
  borrow(loan_no, c_id, b_id, amount, date)
  */
  
  -- 1) Find the number of customers who have loan in each branch
  
  -- 2)List all details of all customers
  
  
  --QUESTION 5 - PROCEDURE
  /*
  EMPLOYEE DATABASE
  employee(emp_id, name, dob, doj, sal, dept_id)
  department(dept_id, dept_name)
  */
  
  -- 1)Write a function for updating the salary of employees working in the department with dept_id=10 by 20%
  
  -- 2)Write a function for employee table which accepts dept_id and return the highest salary in that department. Handle the error if the dept_id does not exist or if the query return more than one maximum
  
  -- 3)Write a function which accepts emp_id and returns employee experience
  
  
  
  --QUESTION 6 - TRIGGER
  /*
  TRIGGERS
  department(dept_id, dept_name)
  employee(emp_id, name, dob, doj, sal, dept_id)
  emp_backup(emp_id, name, dob, doj, sal, dept_id, date_of_op, type_of_op)
  income_tax(emp_id, name, dob, doj, sal, dept_id, tax_amount)
  */
  
  -- 1) Write a trigger which converts employee name into upper case if it is entered in lower case.
  
  -- 2)Write a trigger that stores that data of emplyee table in emp_backup for every delete operation and store the old data for every update operation
  
  -- 3)Write a trigger which displays the message 'updating', 'deleting' or 'inserting' when the corresponding operation is performed on the employee table.
  
  -- 4) Write a trigger that ensures that the emp_id is of the form 'E_____'. If the inserted id is not in this form convert it and then inserted
  
  -- 5)Write a trigger that checks the age of the employee while inserting the record in employee table. If age is negative generate error and display proper message.
  
  -- 6)Create and execute a trigger that allows updation only if the new salary is 80% more than the original salary.
  
  -- 7)Write a trigger to calculate income tax and insert it into income_tax table. Calculate income tax as follows if the annual income is: a)Greater than 15000 but less than 100000 tax is 10% of annual salary. b)Greater than 100000 but less than 200000 tax is 15% of annual salary. c)Greater than 200000 tax is 20$ of annual salary.
  
  