Mongoose解决MongoDB弃用警告（DeprecationWarning）

react项目启动mongodb时，提示如下错误：

DeprecationWarning: Mongoose: `findOneAndUpdate()` and `findOneAndDelete()` without the `useFindAndModify` option set to false are deprecated. See: https://mongoosejs.com/docs/deprecations.html#-findandmodify-
DeprecationWarning: collection.findAndModify is deprecated. Use findOneAndUpdate, findOneAndReplace or findOneAndDelete instead.

找到了这个地址，解决了，现拿来收藏：https://blog.csdn.net/qq_42760049/article/details/98593923?utm_medium=distribute.pc_relevant.none-task-blog-BlogCommendFromBaidu-2&depth_1-utm_source=distribute.pc_relevant.none-task-blog-BlogCommendFromBaidu-2

解决方法：