MongoDB simple command

1. download free Mongodb from https://www.mongodb.com/download-center#community,  I use windows version

2. install mongodb

3. start mongodb

D:\dev\MongoDB\bin>mongod

4. use command line

D:\dev\MongoDB\bin>mongo

5. list current databases

>show dbs

>show databases

6. create a database named 'lyexnode'

use  lyexnode

7. list tables

>show tables

>show collections

8. list users

>show users

9. list roles

>show roles

https://docs.mongodb.com/manual/tutorial/write-scripts-for-the-mongo-shell/#mongo-shell-javascript-file

10. execute users.js file

db = connect("localhost:27017/lyexnode");
cursor = db.users.find();
while ( cursor.hasNext() ) {
   printjson( cursor.next() );
}

D:\dev\MongoDB\bin>mongo localhost:27017/lyexnode users.js

D:\dev\MongoDB\bin>mongo users.js

>load("users.js")

11. find data in table/document

a. query, return all of the columns

db.users.findOne({"name":"admin"}) 

b. query with specified return columns. "_id" is returned by default. It has to  be specified as 0 explicitly

db.users.findOne({"name":"admin"},{_id:0, name:1, password:1})

12. insert/update data to document

db.userInfo.insertOne(   {      name: "sue",      age: 26,      status: "pending"   })

db.userInfo.insert(   {      name: "sue",      age: 26,      status: "A"   })

db.userInfo.insertMany(   [      { name: "sue", age: 26, status: "pending" },      { name: "bob", age: 25, status: "enrolled" },      { name: "ann", age: 28, status: "enrolled" }   ])

db.userInfo.updateOne(   { age: { $lt: 18 } },   { $set: { status: "reject" } })

db.userInfo.updateMany(   { age: { $lt: 18 } },   { $set: { status: "reject" } })

db.userInfo.replaceOne(   { name: "sue" },   { name: "amy", age : 25, score: "enrolled" })

13.delete

db.userInfo.deleteOne(   { status: "reject" })

db.userInfo.deleteMany(   { status: "reject" })

db.userInfo.remove(   { status: "D" })