Mongo DB Commands.txt

===================================Database Commands===================================
1. View all databases
show dbs
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2. Create a new or switch databases 
use dbName
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3. View current Database
db
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4. Delete Database 
  db.dropDatabase()

===================================Collection Commands===================================
1. Show Collections
show collections
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2. Create a collection named 'comments'
db.createCollection('anyname')
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3. Drop a collection named 'comments'
db.comments.drop()

===================================Row(Document) Commands===================================
1. Show all Rows in a Collection 
db.comments.find()
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2. Show all Rows in a Collection (Prettified)
db.comments.find().pretty()
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3. Find the first row matching the object
db.comments.findOne({name: 'bhavya'})
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4. Insert One Row
db.comments.insert
({
    'name': 'bhavya',
    'lang': 'JavaScript',
    'member_since': 5
})
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5. Insert many Rows
db.comments.insertMany
([{
    'name': 'bhavya',
    'lang': 'JavaScript',
    'member_since': 5
    }, 
    {'name': 'ashish',
    'lang': 'Python',
    'member_since': 3
    },
    {'name': 'himanshu',
    'lang': 'React',
    'member_since': 4
}])
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6. Search in a MongoDb Database
db.comments.find({lang:'Python'})
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7. Limit the number of rows in output
db.comments.find().limit(2)
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8. Count the number of rows in the output
db.comments.find().count()
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9. Update a row
db.comments.updateOne
({
     name: 'bhavya'},
     {$set:
     {name: 'bhavya',
     lang: 'mongoDB' 
}})
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10. Insert a updated Row which is not present in the Data
db.comments.updateOne
({
     name: 'bhavya22'},
     {$set:
     {name: 'bhavya22',
     lang: 'mongoDB' }},
     {upsert: true
})
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11.  Mongodb Increment Operator
db.comments.update({name: 'bhavya'},
{$inc:{
    member_since: 2
}})
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12. Mongodb Rename Operator
db.comments.update({name: 'bhavya'},
{$rename:{
    member_since: 'member'
}})
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13. Delete Row 
db.comments.remove({name: 'Cyber'})
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14. Less than/Greater than/ Less than or Eq/Greater than or Eq
db.comments.find({member_since: {$lt: 90}})
db.comments.find({member_since: {$lte: 90}})
db.comments.find({member_since: {$gt: 90}})
db.comments.find({member_since: {$gte: 90}})