Tinned fruit in juice does not have sugar added to it (or any other additives). It might not be in the juice of the same fruit but all fruit juice contains naturally occuring sugars. When you buy a piece of fruit from the supermarket it could be weeks since it has been picked but tinned fruit is often "fresher".
altough many fruit companies are able to lock in vitamins and nutrients of canned fruits, most of them contain useless sugars, preservatives and colorings. Take peaches for example we should almost come up with a new name for canned ones becouse they taste nothing liek the fresh fruit. But at least your eating fruit so keep eating just alternate between the two!