sql.py: mk_flatten_mapping(): Take as_items param to return a list of dict items instead of a dict. Sort preserve cols before other cols. flatten(): Turn on as_items so that cols list is sorted in input order, with preserve cols first. This ensures that if a pkey is provided in preserve, it will be the first col in the generated table.
sql.py: mk_flatten_mapping(): Take as_items param to return a list of dict items instead of a dict. Sort preserve cols before other cols. flatten(): Turn on as_items so that cols list is sorted in input order, with preserve cols first. This ensures that if a pkey is provided in preserve, it will be the first col in the generated table.