Don’t believe the popular myth that says if you have a decorative pot without drainage holes, you can fill simply the bottom with drainage layer of gravel or pot shards and then grow a plant in it. It is very difficult to ensure adequate watering in a pot that has no hole to allow excess water to drain away. Drainage layers only help a smidgen: the soil still tends to remain constantly wet and therefore the plants eventually rot. But you can use a pot with no drainage hole… but as a cachepot (a French word meaning “hidden pot”). In other words, place the plant in a standard flower pot (which does have drainage holes), then set the flower pot inside the decorative pot that doesn’t. And any excess water will drain from the flower pot into the cachepot. After watering, remove the flower pot from the cachepot, then tip it over to pour out any excess water.
Note that many orchids are currently sold in just such a situation: in a flower pot (oddly enough, often transparent!) with drainage holes placed inside a cachepot without any. If you want your orchids to last, always drain the cachepot after watering!