(Oracle)Getting max value across columns

Question

My goal is to get max value for each row. For instance, my table has two columns, and the desired output is, 80,70 and 90 for each row.

I tried this code "SELECT MAX(column1, column2) from my_table" , and it showed error such as ORA-00909:invalid number of argumants

[my_table and the desired output]

Answer 1

Use greatest not max

   with x as (
      select 80 col1, 60 col2 from dual union all
      select 70, 50 from dual union all
      select 80, 90 from dual
    )
    select greatest( col1, col2 )
      from x