Scenario Questions:
===================
1) Write a query that we need to retrieve the names and salaries of employees from the "employees" table, but only for the those working in the finance department.

creating the table:
-------------------

create table employees
(
	employee_Id int,
	first_name varchar(50),
	last_name varchar(50),
	designation varchar(50),
	department varchar(50),
	salary decimal(10,2)
);

-> to deal with whole numbers, oracle is providing another datatype is called as "int"
-> to deal with decimal-point values (floats), we have "decimal" datatype.
Syntax:
	decimal(precision, size);

-> to retrieve:
	select first_name,last_name,salary from employees where department = 'finance';

=====================================
2) Write a query that we need to add a new employee named 'John Doe' to the employees table with a salary of 50000 and department of 'HR'.

insert into employees(employee_Id,first_name,lat_name,desination,department,salary) values(172839,'John','Doe','HR Manager','HR',50000);

3) Write a query to increase the salary of all employees in the IT department by 10%.

update  employees set salary = salary * 1.1 where department = 'IT';

4) Write a query to filter employees with salaries between 30000 and 60000.

select * from employees where salary >= 30000 and salary <= 60000;

5) Write a query to retrieve employees whose salaries are not 40000

select * from employees where salary != 40000;

6) Write a query to find employees whose names contains the letter 'a'.

like operator:
--------------
=> when we want to perform the search operation using "regular expression", we can use "like" operator.

select first_name, last_name from employees 
where first_name like '%a%';