{
	"bsonType": "object",
	"required": ["user_id", "article_id"],
	"permission": {
		"read": "doc.user_id == auth.uid",
		"create": "auth.uid != null",
		"update": "doc.user_id == auth.uid"
		//"delete": "doc.user_id == auth.uid"
	},
	"properties": {
		"_id": {
			"description": "ID，系统自动生成"
		},
		"article_id": {
			"bsonType": "string",
			"description": "文章id，参考opendb-news-articles表",
			"foreignKey": "opendb-news-articles._id"
		},
		"user_id": {
			"bsonType": "string",
			"description": "收藏者id，参考uni-id-users表",
			"forceDefaultValue": {
				"$env": "uid"
			},
			"foreignKey": "uni-id-users._id"
		},
		"last_time": { //设计策略是多次看同一个文章只做一次记录，重复看的文章时间更新为当前时间
			"bsonType": "timestamp",
			"description": "最后一次看的时间",
			"defaultValue": {
				"$env": "now"
			}
		}
	}
}