I have a lot of these. They have little thorns near the base of the stem, so they are tricky to pull up without gloves on. They are very resilient and when pulled they usually break off at ground level and come right back up in a few days.
Some kind of wild Solanum. A weedy nightshade. We have a smaller variety here in Virginia. Maybe this one is the dreaded "Soda apple" which gets bushy. Some have yellow fruit, some red. They are considered invasive weeds by most people.
If the flower pedals are lavender to purple with yellow stamens and pistils (at first tightly bound together) and fruit is round-2cm dia. and dries to a browninsh yellow it's probably what we call 'wild tomato' the genus I believe is 'solanum'