PostgreSQL(part-3)

update

update employee set salary=30000 where empid=111;

empid	name	designation	dept	salary
101	Agaran	Team Lead	DB	50000
123	Kavin	Software Engineer	DB	25000
101	Arul	Team Lead	Front End	35000
124	Viyan	Software Engineer	AI	27000
118	Pari	SQL Developer	45000	45000
111	Mugilan	Team Lead	35000	30000

Delete

delete from employee where empid=111;

empid	name	designation	dept	salary
101	Agaran	Team Lead	DB	50000
123	Kavin	Software Engineer	DB	25000
101	Arul	Team Lead	Front End	35000
124	Viyan	Software Engineer	AI	27000
118	Pari	SQL Developer	45000	45000

truncate
Remove all data but keep the table remains
drop
Remove the table completely

order by

select * from employee order by salary;

empid	name	designation	dept	salary
123	Kavin	Software Engineer	DB	25000
124	Viyan	Software Engineer	AI	27000
101	Arul	Team Lead	Front End	35000
118	Pari	SQL Developer	45000	45000
101	Agaran	Team Lead	DB	50000

select * from employee order by salary desc;

empid	name	designation	dept	salary
101	Agaran	Team Lead	DB	50000
118	Pari	SQL Developer	45000	45000
101	Arul	Team Lead	Front End	35000
124	Viyan	Software Engineer	AI	27000
123	Kavin	Software Engineer	DB	25000

group by **
Aggregrate function
**count()

select count(*) from employee;

 5

sum()

select sum(salary) from employee;

182000

avg()

select avg(salary) from employee;

36400.000000000000

min()

select min(salary) from employee;

25000

max()

select max(salary) from employee;

50000