引用

1. 2019.3.5 国家卫生健康委办公厅关于印发医院智慧服务分级评估标准体系（试行）的通知
2. 医院智慧服务分级评估标准体系(试行)

Tips

• By default, log4js level for default category is set to OFF, thus not outputting any logs. To turn on logging, level must be set other than OFF.
• Levels: TRACE -> DEBUG -> INFO -> WARN -> ERROR -> FATAL

Ref

Concepts

What is MongoDB

• A leading document, NoSQL database.
• Highly available, scalable.
• Flexible schema.

Document and scale-out

• Instead of storing tablesof rows or columns like RDBMS, record in MongoDB is document based in BSON, which is a binary representation for JSON.
• Document format makes data:
  • highly flexible
  • allowing varaitions in structure
  • allowing partial complete data
  • can embed one document in another
• Based on scale-out architecture, a structure which enables many small machines to work together to create fast systems and handle huge amounts of data.
  • With it, MongoDB can scale.

BSON Example:

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{
  "_id": 1,
  "name": {
    "first": "Ada",
    "last": "Lovelace"
  },
  "title": "The First Programmer",
  "interests": ["mathematics", "programming"]
}

Glossary

• Database: Container for collections.
• Colletion: A group of documents. No schema enforced. But documents should be grouped for similar purpose.
• Document: A set of key-value pairs. Dynamic schema.
• Embedded Documents: Embedded documents are like join in SQL.

When to use

• Big Data
• Content Management and Delivery
• Mobile and Social Infrastructure
• Data Hub

Hands-on

Installation and running

• Install MongoDB Community Server.
• Go to <install_folder>/bin, run mongod.
  • You got: NonExistentPath: Data directory: D:\\data\\db\\ not found. Need to override this pre-configuration first.
• mongod can run with command line parameters or read from a config file. Let’s just use command line first.
• Run mongod --dbpath D:/mongodata/data --logpath D:/mongodata/log/mongod.log --port 27017. 27017 is default port.
• Now the server is on.

MongoDB shell

• For servers >= 6.0, shell not longer shipped along with.
• Download mongosh

MongoDB Compass

• The official GUI tool for MongoDB.

Add proxy to heroku login

Comparison

Ref

1. CORS tutorial
2. 关于CORS和withCredentials

Ref

1. Javascript this

What is this

• this in Javascript refers to the context of the statement in which it is being executed.

Ref

1. Pug - getting started

What and why

• Pug is an html template engine which simplies html coding.
• Pug‘s predecessor is the well-known jade.