我正在尝试将新字段(日期类型的LastLoginDate)添加到现有集合中。这是我的示例脚本:db.createCollection("MyTestCollection",{"validator":{"$or":[{"username":{"$type":"string"}},{"notes":{"$type":"string"}}]}})db.getCollectionInfos({name:"MyTestCollection"});[{"name":"MyTestCollection","options":{"validator":{"$or":[{"username":{"$ty