Mongo.md

Mongo

Run Mongo container

docker run -d --name mongo -p "27017:27017" --restart always mongo

Show all available DBs

show dbs

Select a DB to use

use <db_name>

Show all collections within the selected DB

show collections

Show all records in a given collection in a DB

db.<collection_name>.find().pretty()

Insert a document into a collection

db.<collection_name>.insert( { item: "car", qty: 24 } )

Delete a single document that matches a given filter from a collection

db.<collection_name>.deleteOne( { "<key>" : <value>) } );

Delete all documents that match a given filter from a collection

db.<collection_name>.deleteMany( { "<key>" : <value> } );

Delete all documents from a collection

db.<collection_name>.remove({})

Delete a collection

db.<collection_name>.drop()

Delete a DB (run 'use <db_name_to_drop>'' first)

db.dropDatabase()

Find all documents according to a nested field

db.<collection_name>.find( { "<top_level_field_name>.<second_level_field_name>": "<field_value_to_find>" } ).pretty()

Find all documents that match 2 fields

db.<collection_name>.find(
    {$and:[
        {"<top_level_field_name>.<second_level_field_name>":{"$in":["<field_value_to_find>"]}},
        {"<top_level_field_name>.<second_level_field_name>":{"$in":["<field_value_to_find>"]}}
    ]}
).pretty()

Show status of cluster, including which node is primary (see "syncingTo" field)

rs.status()

Find documents with a specific field being a non-empty string

db.collection.find({"lastname" : {"$exists" : true, "$ne" : ""}})

Find the N most recently added documents

db.collection.find().limit(N).sort({$natural:-1}).pretty()

Find oldest/newest record

db.people.insert({name: "Bob", age: 42, dateAdded: new Date()})
db.people.insert({name: "Sally", age: 58, dateAdded: new Date()})

// find oldest record by date field
db.people.find().sort({dateAdded: 1}).limit(1)
[
  {
    _id: ObjectId("64147bdf169b4546e6db2970"),
    name: 'Bob',
    age: 42,
    dateAdded: ISODate("2023-03-17T14:40:31.415Z")
  }
]

// find newest record by date field
db.people.find().sort({dateAdded: -1}).limit(1)
[
  {
    _id: ObjectId("64147be5169b4546e6db2971"),
    name: 'Sally',
    age: 58,
    dateAdded: ISODate("2023-03-17T14:40:37.035Z")
  }
]

Export collection to csv

docker exec -i 418f46e5595d  mongoexport --db saveInfo --collection infoobjects --type=csv --fields _id,postLink,postTitle,contactPhone --out ./info.csv