select *
from l_employees;

select employee_id
from l_employees;

select employee_id,
       first_name,
       last_name
from l_employees;

select employee_id as employee_number,
       first_name,
       last_name
from l_employees;

select employee_id as [employee number],
       first_name,
       last_name
from l_employees;


select employee_id as [employee number],
       first_name,
       last_name,
       'Excellent Worker' as comments,
       10 as [job rating]
from l_employees;

select manager_id
from l_employees;

select distinct manager_id
from l_employees;


select distinct manager_id,
                credit_limit
from l_employees;

select employee_id,
       last_name,
       first_name
from l_employees
order by last_name;

select employee_id,
       last_name,
       first_name, 
       dept_code
from l_employees
order by dept_code,
         last_name;

select employee_id,
       last_name,
       first_name
from l_employees
order by 2;

select employee_id,
       last_name,
       first_name, 
       dept_code
from l_employees
order by 4,
         2;

select employee_id as employee_number,
       last_name as family_name,
       first_name
from l_employees
order by last_name;

select last_name,
       first_name
from l_employees
order by last_name desc;

select dept_code,
       last_name,
       first_name
from l_employees
order by dept_code,
         last_name desc;

select dept_code,
       last_name,
       first_name
from l_employees
order by 1,
         2 desc;

select employee_id,
       first_name,
       last_name
from l_employees
where manager_id = 203;

select employee_id,
       first_name,
       last_name
from l_employees
where manager_id = 203
order by last_name;

select dept_code,
       first_name,
       last_name
from l_employees
where dept_code = 'sal';

select first_name,
       last_name
from l_employees
where hire_date = #01-jul-2008#;

select last_name,
       first_name,
       credit_limit
from l_employees
where credit_limit < 20.00;

select dept_code,
       first_name,
       last_name
from l_employees
where not (dept_code = 'sal');

select first_name,
       last_name,
       credit_limit
from l_employees
where credit_limit in (25.00, 30.00);

select first_name,
       last_name,
       credit_limit
from l_employees
where credit_limit not in (25.00, 30.00);

select employee_id,
       last_name
from l_employees
where manager_id between 201 and 202;

select employee_id,
       last_name
from l_employees
where manager_id not between 201 and 202;

select first_name,
       last_name,
       dept_code,
       phone_number as extention
from l_employees
where dept_code like 's*';

select first_name,
       last_name,
       dept_code,
       phone_number as extention
from l_employees
where dept_code not like 's*';

select first_name,
       last_name,
       hire_date
from l_employees
where hire_date is null;

select first_name,
       last_name,
       hire_date
from l_employees
where hire_date is not null;