I have converted incoming Excel files to csv files. My incoming files vary in structure, and so do have different headers and also different field names. I have the header field names in an attribute.
How can I employ a QueryRecord or an ExecuteSQL processor to return a count for each field of records that have values in them (non-whitespace, non-empty, non-null values)? They vary by flowfile, so the field names would have to be read from the attribute into the SQL query. I need my query to be dynamic to the field structure, and cannot fix them by name because they change depending on the raw data. Using Query Record seems to depend on a Record Reader and on a Record Writer. Is it possible to configure these dynamically if every flowfile will have variations in field names and in number of fields in its header?