SQL Queries

use sql_hr;

select *

from employees;

select *

from employees

where first_name regexp 'y$';

select *

from employees

where job_title regexp '^s|t$';

select *

from employees

where job_title regexp '^s|t$'

order by salary;

select *

from employees

where job_title regexp '^s|t$'

and last_name regexp 'n$'

order by salary;

select count(distinct employee_id) as employee_id_count

from employees;

select avg(salary) as avg_salary

from employees;

select max(salary) as max_salary

from employees;

select min(salary) as min_salary

from employees;

select *

from employees as e

left join offices as o

using(office_id)

union

select *

from employees as e

right join offices as o

using(office_id);

select *

from employees as e

left join offices as o

using(office_id)

union

select *

from employees as e

right join offices as o

using(office_id);

select count(*) as row_count

from(select *

from employees as e

left join offices as o

using(office_id)

union

select *

from employees as e

right join offices as o

using(office_id))

as full_join_result;