[{"date":"01-01-2022","orderid":1001},{"date":"01-01-2022","orderid":1001},{"date":"01-01-2022","orderid":1002},{"date":"02-01-2022","orderid":1003},{"date":"02-01-2022","orderid":1003},{"date":"02-01-2022","orderid":1003},{"date":"02-01-2022","orderid":1004},{"date":"02-01-2022","orderid":1005},{"date":"03-01-2022","orderid":1006},{"date":"03-01-2022","orderid":1007}]

db.collection.aggregate([{"$group":{"_id":"$date","orderIds":{"$addToSet":"$orderid"}}},{"$project":{"_id":0,"date":"$_id","count_orderid":{"$size":"$orderIds"}}}])