- make-db-field type maxlen mandatory?procedure
Return a db-field object which can be used with autoform's extra-fields keyword parameter.
type (a string) can be any valid database type (e.g., "boolean", "text") or the special ones: "password" and "hidden".
maxlen is the maximum length of the input for the field (for those which length makes sense). When it doesn't make sense (e.g., "boolean"), #f can be used.
mandatory? is a boolean to indicate whether the field is mandatory.