MongoDB如何更新多级文档的数据

{name: '岛上码农', documents: ['Flutter入门与实战', '高性能MySQL', 'MongoDB专业指北']}

db.author.update(
  {name: '岛上码农', documents: 'MongoDB专业指北'}, 
  {'$set': {'documents.$': 'MongoDB不专业指北'}}
);

{
  name: '岛上码农', 
  documents: [
    {name: 'Flutter入门与实战', score: 80}, 
    {name: '高性能MySQL', score: 90}, 
    {name: 'MongoDB专业指北', score: 85}
  ]
}

db.author.update(
  {name: '岛上码农', 'documents.name': 'MongoDB专业指北'},
  {'$set': {
    	'documents.$.name': 'MongoDB不专业指北', 
    	'documents.$.score':88}
  }
);

{
  name: '岛上码农', 
  scores: {
    view:  18800, 
    praise: 290, 
    followers: 105
	}
}

db.author.update(
  {name: '岛上码农'}, 
  {'$set': {'scores.praise': 291}}
);

{
  name: '岛上码农', 
  scores: {
    view:  18800, 
    praise: 290, 
    followers: 105,
    platform: ['掘金', '公众号']
	}
}

db.author.update(
  {'name': '岛上码农', 'scores.platform': '公众号'},
  {'$set': {'scores.platform.$':'微信公众号'}}
);

db.author.update(
  {name: '岛上码农'}, 
  {$push: {homepage: 'https://juejin.cn/user/70787819648695'}}
);

db.author.update(
  {name: '岛上码农'}, 
  {$pull: {homepage: 'https://juejin.cn/user/70787819648695'}}
);

{
  name: '岛上码农',
	scores : {
		view: 18800,
		praise: 290,
		followers: 105,
		platform: ['掘金', '公众号', '其他1', '其他2']
	}
}

// 移除第一个元素
db.author.update({name: '岛上码农'}, {$pop: {'scores.platform': -1}});
// 移除最后一个元素
db.author.update({name: '岛上码农'}, {$pop: {'scores.platform': 1}});