UseWho gives me an example of the total salary format comma

Question

Who gives me an example of the total salary this

 Select sum(to_char(salary,'9,999,999')) from employees;

Output Ora-01722

Answer 1

You are converting to character before you complete the sum, which must be done to a number. Reverse the order of your functions - do all the math before you change the data type to char:

select to_char(sum(salary),'9,999,999') from employees;