mongodb随机返回N条结果

mongodb随机返回N条结果：

用$sample (aggregation)方法，具体命令为：
db.<数据库>.aggregate( [ { $sample: { size: N } } ] ) N为条数

异步携程查询

class Image_Pust_():
    ####  文档地址  https://www.cnblogs.com/aduner/p/13532504.html
    client = motor.motor_asyncio.AsyncIOMotorClient('数据库链接')  # 使用链接访问
    sss = client.sss    # client.数据库集合
    test1 = sss.test1    # 数据库

    async def Rand_find(self, document=None):
        c = Image_Pust_().sss.test1
        # async for document in c.find():
        #     print(document)
        a = c.aggregate([{"$sample": {"size": 15}}])   # 查询15条数据
        return [i async for i in a]     #  返回数据