I don't get it. What is empty column ? If there is no field separator (originally it is , ) then how will TB understand what do You need import at all ? Or I understand something wrongly ?
For example this :
ID;Active (0/1);Name *;Categories (x,y,z...);Price tax excluded or Price tax included
1;test;;;
It is 5 values. Given are only two, but TB rewrites all. And if there is no value, then erases existing.
Does column mean any of these 5 values ? So at the moment column 1 has value 1, column 2 has value test etc ?