reference
- CodeWithHarry video -> https://youtu.be/oSIv-E60NiU
- Official Documentation -> https://www.mongodb.com/docs/
- freeCodeCamp getting started -> https://www.freecodecamp.org/news/get-started-with-mongodb-atlas/
what is MongoDb?
-
production ready database
-
document based database
difference between mongo and mongod
- mongo : command line shell
- mongod : mongo daemon, hosts the process
comparison of mongodb with mysql
- sql equivalent to tables in excel
| sql | mongodb |
|---|---|
| database | database |
| tables | collections |
| rows | documents (BSON) |
| columns | fields |
install mongodb
- mongodb community server
- mongodb compass
capped collection -> limiting the number of documents
- bson has more types than json
basic commands
Database commands
- View all databases
show dbs; - Make a new database or switch to a database
use comments - Show which database
db - Delete database
db.dropDatabase()
Collection commands
- Show all collections
show collections - Make a new collection named comments
db.createCollection('myComments') - Delete a collection
db.<name_of_collection>.drop()
Rows columns
-
Show all rows in the collection
db.<name_of_collection>.find() -
Find first row matching the object
db.<name_of_collection>.find({name: "Chaitanya"}) -
Show all rows in the collection (prettified)
db.<name_of_collection>.find().pretty() -
Search for rows
db.<name_of_collection>.find({lang: 'Python'}) -
Limit find results
db.<name_of_collection>.find().limit(2) -
Insert one Row
db.<name_of_collection>.insert({ 'name': 'Chaitanya', 'lang': 'JavaScript', 'member_since': 2018 }) -
Insert many Rows `db.<name_of_collection>.insertMany([ { ’name’: ‘Chaitanya’, ’lang’: ‘JavaScript’, ‘member_since’: 2018 }, { ’name’: ‘Shahare’, ’lang’: ‘Python’, ‘member_since’: 2018 }, { ’name’: ‘Chaitanya’, ’lang’: ‘JavaScript’, ‘member_since’: 2018 },
])`
-
Delete Row
db.<name_of_collection>.remove({name: "shahare"}) -
Count the number of rows in the output
db.<name_of_collection>.find().count() -
Sorting
db.<name_of_collection>.find().sort({member_since: -1}).pretty() -
Update a rows
db.<name_of_collection>.update({name: 'Chaitanya'}, { 'name': 'Chaitanya', 'lang': 'C++', 'member_since': 2009 }) -
If you want to make a new object, if no matches are found, add a option
db.<name_of_collection>.update({name: 'Chaitanya'}, { 'name': 'Chaitanya', 'lang': 'C++', 'member_since': 2009 }, {upsert: true})
Update operators
- Increment update operator
$incdb.<name_of_collection>.update({name: 'shahare'}, {$inc: { member_since: 2 }}) - Rename update operator
$renamedb.<name_of_collection>.update({name: 'shahare'}, {$rename: { member_since: 2 }})
Filters
- Less than
$ltdb.<name_of_collection>.find({ member_since: {$lt: 90} }) - Less than equal to
$ltedb.<name_of_collection>.find({ member_since: {$lte: 90} }) - Greater than
$gtdb.<name_of_collection>.find({ member_since: {$gt: 90} }) - Greater than equal to
$gtedb.<name_of_collection>.find({ member_since: {$gte: 90} })
MongoDb atlas
- MongoDb on cloud
- Organisation > Project > Cluster
- Database user
- Connect via react/compass
- Add a connection IP
- Connection string