1 ½ c vinegar (red wine vinegar is best)
1 c oil (extra virgin olive oil is too strong for this use; try "light" or a vegetable oil)
1 ½ c sugar
½ t salt
½ t pepper
½ t celery seed
Drain beans. Rinse well to remove as much of the sugars in the canning liquid as possible, as these are responsible for the "problems" with legumes.
Make dressing, toss vegetables in it, and refrigerate overnight, covered.