SQL ROW_NUMBER() and OVER() method case study

create table TEST_ROW_NUMBER_OVER(
       id varchar(10) not null,
       name varchar(10) null,
       age varchar(10) null,
       salary int null
);
select * from TEST_ROW_NUMBER_OVER t;
 
insert into TEST_ROW_NUMBER_OVER(id,name,age,salary) values(1,'a',10,8000);
insert into TEST_ROW_NUMBER_OVER(id,name,age,salary) values(1,'a2',11,6500);
insert into TEST_ROW_NUMBER_OVER(id,name,age,salary) values(2,'b',12,13000);
insert into TEST_ROW_NUMBER_OVER(id,name,age,salary) values(2,'b2',13,4500);
insert into TEST_ROW_NUMBER_OVER(id,name,age,salary) values(3,'c',14,3000);
insert into TEST_ROW_NUMBER_OVER(id,name,age,salary) values(3,'c2',15,20000);
insert into TEST_ROW_NUMBER_OVER(id,name,age,salary) values(4,'d',16,30000);
insert into TEST_ROW_NUMBER_OVER(id,name,age,salary) values(5,'d2',17,1800);

select id,name,age,salary,row_number()over(order by salary desc) rn
from TEST_ROW_NUMBER_OVER t

select id,name,age,salary,row_number()over(partition by id order by salary desc) rank
from TEST_ROW_NUMBER_OVER t

select * from(select id,name,age,salary,row_number()over(partition by id order by salary desc) rank
from TEST_ROW_NUMBER_OVER t)
where rank <2

select id,name,age,salary,row_number()over(order by salary desc) rank
from TEST_ROW_NUMBER_OVER t where age between '13' and '16'

select email,customerID, ROW_NUMBER() over(order by psd) as rows from QT_Customer

select DID,customerID,totalPrice,ROW_NUMBER() over(order by totalPrice) as rows from OP_Order

select ROW_NUMBER() over(partition by customerID order by totalPrice)
 as rows,customerID,totalPrice,DID from OP_Order

with tabs as  
(  
select ROW_NUMBER() over(partition by customerID order by totalPrice)
 as rows,customerID,totalPrice,DID from OP_Order  
 )  
select MAX(rows) as 'Number of orders',customerID from tabs 
group by customerID

    with tabs as  
     (  
    select ROW_NUMBER() over(partition by customerID order by insDT) 
as rows,customerID,totalPrice,DID from OP_Order  
    )  
     select * from tabs  
    where totalPrice in   
    (  
    select MIN(totalPrice)from tabs group by customerID  
     )

    with tabs as  
    (  
    select ROW_NUMBER() over(partition by customerID order by insDT) as rows,* from OP_Order  
    )  
    select * from tabs where rows = 1 
    select * from OP_Order

    select   
    ROW_NUMBER() over(partition by customerID order by insDT) as rows,  
    customerID,totalPrice,DID  
    from OP_Order where insDT>'2011-07-22'