MongoDB CRUD Operations

Data selection and Imports

Prepare a cluster on your Atlas storage

cluster name: 'school' database_name: 'dbi' collection_name: 'teachers'

username: 5ahif password: 5ahif

Find/Extract Data

My data:

from 'htlstp.ac.at/lehrer' convertet to JSON via gemini ai (easier than webscraping and possible because of the small data size)

{
  "meta": {...},
    "data": [
}

Import the data

to import data into mongodb, the options are:

• mongoimport tool
• write a script (e.g. in python)
• use a GUI tool (e.g. MongoDB Compass)
• use the mongo shell

I used the mongodb compass

How the 5ahif user can access the dbi database:

mongosh "mongodb+srv://school.fu7deyq.mongodb.net/" --apiVersion 1 --username 5ahif

and then switch to the dbi database:

use dbi

CRUD Operations

• Add one suitable document with fictional data.
• Formulate three functional questions regarding the data in your collection. Create three distinctive queries for these questions.
• Update your data with three distinct update statements with suitable filters. One of the statements needs to be an upsert statement.
• Remove at least one document with a proper delete statement.
• Provide and describe queries that show the effects of your statements.

Create (Insert) a Document

db.teachers.insertOne(
  {
    "name": "Friedl",
    "firstname": "Benjamin",
    "subject": ["DBI"],
    "age": 18,
    "fulltime": true,
    "hobbies": ["Going to school", "Joking"]
  }
)

Read (Find) Documents

Prof. Raab

db.teachers.find({ "name": { $regex: "Raab" } })

all Abteilungsvorstand

db.teachers.find({ "role": "Abteilungsvorstand" })

How many teachers are in the department 'Informatik'?

db.teachers.countDocuments({ "departments": "Informatik" })

Update Documents

db.teachers.updateOne(
  { "name": "Friedl" },
  { $set: { "age": 19 } }
)

db.teachers.updateMany(
  { "fulltime": true },
  { $set: { "hobbies": [] } }
)

Upsert Example

Upsert: if the document does not exist, create it.

db.teachers.updateOne(
  { "name": "Mustermann" },
  { $set: { "firstname": "Max", "age": 30, "subject": ["Math"], "fulltime": false } },
  { upsert: true }
)

db.teachers.updateMany(
  { "department": "Informatik" },
  { $set: { "image": "htl-logo.png" } }
)

Delete Documents

db.teachers.deleteOne({ "name": "Friedl" })