Not adults, but I have found dragon fly larvae in my tanks. Several members on here have. No idea why they would come inside to lay their eggs in a tank unless it is the drought we have been having here.
Ive found all sorts of flying insects in my tanks I usually just feed them to my cichlids. Waste not want not.
I have read that dragonfly larvae can attack your fish.
I can see this happening with smaller fish, but a larger aggressive feeding fish should have no problem.
Dragonfly larvae are opportunist. They will eat what they can catch. However, most fish are safe from them. I have them in my outdoor frog pond and have never seen them eat a tadpole. The ones in my tank were with fry and the dragon fly larvae never bothered them. I just put the larvae in my outdoor pond. Can always use more dragonflies to eat the mosquitoes.