I'm not sure if you understand the difference between series and parallel?
You can place the lights in a row, but I'm specifically addressing the wiring. Wiring in series is when you attach the hot to the first lamp connect the first lamp to the second. connect the second to the third, and finally wire the third to the neutral return wire. This will not work!
You need to wire in parallel where the hot black is attached to the black of all lamps, and the white from all lamps is attached to the white return leg.
Hope this helps. Its hard to say what someone is trying to do without seeing it.