How to merge values of two rows into single row for same id?

Question

I have data in a table(list) as shown below,

 id      no1   no2
 1000    0     511
 1000    820    0

I need data like shown below,

Answer 1

You can use sum or max:

select id,max(no1),max(no2) from tab_name group by id;

or

select id,sum(no1),sum(no2) from tab_name group by id;

Answer 2

simple group by with summation will work for you

SELECT 
  ID,
  SUM(NO1) NO1,
  SUM(NO2) NO2
FROM Table1
Group by ID