MongoDB Exercise :2
studentsB> db.aids.find().count()
4
studentsB> db.aids.find().count()
4
studentsB> db.aids.find().limit(3)
[
{
_id: ObjectId("66fa2428ca0fc631a23b264f"),
SRN: 201,
SName: 'A',
yr: 3
},
{
_id: ObjectId("66fa2479ca0fc631a23b2650"),
SRN: 202,
SName: 'B',
yr: 3
},
{
_id: ObjectId("66fa249eca0fc631a23b2652"),
SRN: 303,
SName: 'CC',
yr: 3
}
]
studentsB> db.aids.find().limit(2)
[
{
_id: ObjectId("66fa2428ca0fc631a23b264f"),
SRN: 201,
SName: 'A',
yr: 3
},
{
_id: ObjectId("66fa2479ca0fc631a23b2650"),
SRN: 202,
SName: 'B',
yr: 3
}
]
studentsB> db.aids.find().sort()
[
{
_id: ObjectId("66fa2428ca0fc631a23b264f"),
SRN: 201,
SName: 'A',
yr: 3
},
{
_id: ObjectId("66fa2479ca0fc631a23b2650"),
SRN: 202,
SName: 'B',
yr: 3
},
{
_id: ObjectId("66fa249eca0fc631a23b2652"),
SRN: 303,
SName: 'CC',
yr: 3
},
{
_id: ObjectId("66fa361cefea40aa66eff667"),
SRN: 304,
SName: 'DD',
yr: 2
},
{
_id: ObjectId("66fa3631efea40aa66eff668"),
SRN: 305,
SName: 'EE',
yr: 2
}
]
studentsB> db.aids.find().sort({SRN:1})
[
{
_id: ObjectId("66fa2428ca0fc631a23b264f"),
SRN: 201,
SName: 'A',
yr: 3
},
{
_id: ObjectId("66fa2479ca0fc631a23b2650"),
SRN: 202,
SName: 'B',
yr: 3
},
{
_id: ObjectId("66fa249eca0fc631a23b2652"),
SRN: 303,
SName: 'CC',
yr: 3
},
{
_id: ObjectId("66fa361cefea40aa66eff667"),
SRN: 304,
SName: 'DD',
yr: 2
},
{
_id: ObjectId("66fa3631efea40aa66eff668"),
SRN: 305,
SName: 'EE',
yr: 2
}
]
studentsB> db.aids.find().sort({SRN:-1})
[
{
_id: ObjectId("66fa3631efea40aa66eff668"),
SRN: 305,
SName: 'EE',
yr: 2
},
{
_id: ObjectId("66fa361cefea40aa66eff667"),
SRN: 304,
SName: 'DD',
yr: 2
},
{
_id: ObjectId("66fa249eca0fc631a23b2652"),
SRN: 303,
SName: 'CC',
yr: 3
},
{
_id: ObjectId("66fa2479ca0fc631a23b2650"),
SRN: 202,
SName: 'B',
yr: 3
},
{
_id: ObjectId("66fa2428ca0fc631a23b264f"),
SRN: 201,
SName: 'A',
yr: 3
}
]
studentsB> use db123
switched to db db123
db123> db.col1.insert({SNo:1,Name:'aa')}
Uncaught:
SyntaxError: Unexpected token, expected "," (1:31)
> 1 | db.col1.insert({SNo:1,Name:'aa')}
| ^
2 |
db123> db.col1.insert({SNo:1,Name:'aa'})
DeprecationWarning: Collection.insert() is deprecated. Use insertOne, insertMany, or bulkWrite.
{
acknowledged: true,
insertedIds: { '0': ObjectId("66fa37b8efea40aa66eff669") }
}
db123> db.col2.insert({SNo:1,Name:'bb'})
{
acknowledged: true,
insertedIds: { '0': ObjectId("66fa37caefea40aa66eff66a") }
}
db123> show collections
col1
col2
db123> db.col1.drop()
true
db123> show collections
col2
db123> db.dropDatabase()
{ ok: 1, dropped: 'db123' }
db123> show dbs
123 40.00 KiB
4B_AIDS 72.00 KiB
OneBBank 72.00 KiB
abc123 72.00 KiB
admin 40.00 KiB
banks 40.00 KiB
config 108.00 KiB
countries 40.00 KiB
csbs 128.00 KiB
db 40.00 KiB
db1 72.00 KiB
db3 72.00 KiB
db5 56.00 KiB
empAV 72.00 KiB
employeeAV 72.00 KiB
employeeHarshil 72.00 KiB
employees 136.00 KiB
local 112.00 KiB
my_db 80.00 KiB
my_dbpy 72.00 KiB
saibaba 72.00 KiB
sports 72.00 KiB
student 48.00 KiB
studentDB 72.00 KiB
studentsB 72.00 KiB
studentsB> db.aids.find()
[witched to db studentsB
{
_id: ObjectId("66fa2428ca0fc631a23b264f"),
SRN: 201,
SName: 'A',
yr: 3
},
{
_id: ObjectId("66fa2479ca0fc631a23b2650"),
SRN: 202,
SName: 'B',
yr: 3
},
{
_id: ObjectId("66fa249eca0fc631a23b2652"),
SRN: 303,
SName: 'CC',
yr: 3
},
{
_id: ObjectId("66fa361cefea40aa66eff667"),
SRN: 304,
SName: 'DD',
yr: 2
},
{
_id: ObjectId("66fa3631efea40aa66eff668"),
SRN: 305,
SName: 'EE',
yr: 2
}
]
studentsB> db.aids.createIndex({SRN:1})
SRN_1
studentsB> db.aids.createIndex({SRN:-1})
SRN_-1
studentsB> db.aids.dropIndex({SRN:-1})
{ nIndexesWas: 3, ok: 1 }
studentsB>
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