I'm trying to insert data to SQL database. I have all the columns in the same order as the data flow. But I'm getting this "Invalid column name name_of_the_actual_data_column" error
Column order won't matter, but exact column names will. Your SQL implementation probably isn't picky enough to require case-sensitive matches, but spaces and punctuation will matter. With Specify database fields unchecked, all field names MUST exist as columns in the target table.
I've found a good way to troubleshoot SQL inserts is to put a Select step before the Table output and make sure that you're really only getting the columns you want to insert.
You can also right-click on the Table output step and choose Input fields... to see the column metadata being passed into the step.