mongodb基本用法笔记

introduction

this note include mongodb installation, basic usage, user authority

installation

reference: docs.mongodb.com/manual/tuto…

• add key

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 9DA31620334BD75D9DCB49F368818C72E52529D4

• add to sources.list (Ubuntu 16.04 (Xenial))

echo "deb [ arch=amd64,arm64 ] https://repo.mongodb.org/apt/ubuntu xenial/mongodb-org/4.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-4.0.list

• install

sudo apt-get update
sudo apt-get install -y mongodb-org

• run backgroud

default port: 27017, path: /var/lib/mongodb, can be self-define

/usr/bin/mongod -f /etc/mongod.conf &

or

mongod --port 27017 --dbpath /data/db

• mongod.conf

if wanna access db through public ip set bindIp: 0.0.0.0 or specified an ip

root@ubuntu:/etc# cat mongod.conf 
# mongod.conf

# for documentation of all options, see:
#   http://docs.mongodb.org/manual/reference/configuration-options/

# Where and how to store data.
storage:
  dbPath: /var/lib/mongodb
  journal:
    enabled: true
#  engine:
#  mmapv1:
#  wiredTiger:

# where to write logging data.
systemLog:
  destination: file
  logAppend: true
  path: /var/log/mongodb/mongod.log

# network interfaces
net:
  port: 27017
  bindIp: 0.0.0.0
  #bindIp: 127.0.0.1

# how the process runs
processManagement:
  timeZoneInfo: /usr/share/zoneinfo

basic usage

• windows install(ignore)

reference: docs.mongodb.com/manual/tuto…

• start

almost all operation has one(db.insertOne()) and many(db.insertMany()) function, i only record one operation

/usr/bin/mongo

or

mongo

• use db(create operation)

reference: docs.mongodb.com/manual/refe…

mongodb default dbs "admin", "config", "local", no collections(table), no documents(table's record)

> show dbs
admin            0.000GB
config           0.000GB
local            0.000GB
> show databases
admin            0.000GB
config           0.000GB
local            0.000GB
> show tables       # output nothing because of no table
> show collections  # output nothing because of no collections
>

use db show the db using now, use dbname to switch to db existed or use self defined dbname to create db, we can use self defedined db and table, such as self_defined_db and self_defined_db's table first_table

> db
test
> use test
switched to db test
> use self_defined_db
switched to db self_defined_db
> db.first_table.insertOne({name: "vickey", age: 18})
{
	"acknowledged" : true,
	"insertedId" : ObjectId("5d0226daaea0917927c50511")
}
> db.first_table.insertOne({name: "vickey1", age: 19, sex: "male"})
{
	"acknowledged" : true,
	"insertedId" : ObjectId("5d02fb87f227aaf10b436012")
}
> show collections
first_table

• query operation

as we can see, we can use db.tablename.find({key: value}) to find record in table exsited, but can't find record in table not exsited, such as second_table(output nothing), we should create them firstly. we can find all documents(records) by db.tablename.find().pretty()

> db.first_table.find({name: "vickey"})
{ "_id" : ObjectId("5d0226daaea0917927c50511"), "name" : "vickey", "age" : 18 }
> db.first_table.find({name: "vicke"})
> db.second_table.find({name: "vickey"})
> 
> db.first_table.find().pretty()
{
	"_id" : ObjectId("5d02fb66f227aaf10b436011"),
	"name" : "vickey",
	"age" : 18
}
{
	"_id" : ObjectId("5d02fb87f227aaf10b436012"),
	"name" : "vickey1",
	"age" : 19,
	"sex" : "male"
}

• update operation

I update the record's name, output "modifiedCount": non-zero if successed, then we only find the record with new name

> db.first_table.updateOne({name: "vickey"}, {$set: {name: "vickey wu"}})
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 }
> db.first_table.find({name: "vickey"})
> db.first_table.find({name: "vickey*"})
> db.first_table.find({name: "vickey wu"})
{ "_id" : ObjectId("5d0226daaea0917927c50511"), "name" : "vickey wu", "age" : 18 }

• replace operation

different with update operation, replace operation would replace all keys in the record by the one you replace. from the follow example we can see that the record key age also be replaced with nothing, in other word, be deleted, because we didn't replace key age with an actual value

> db.first_table.replaceOne({name: "vickey wu"}, {name: "vickey"})
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 }
> db.first_table.find({name: "vickey"})
{ "_id" : ObjectId("5d0226daaea0917927c50511"), "name" : "vickey" }      # key 'age' was deleted

if every key in the record were given, then would no key was deleted

> db.first_table.replaceOne({name: "vickey"}, {name: "vickey", age: 18})
{ "acknowledged" : true, "matchedCount" : 1, "modifiedCount" : 1 }
> db.first_table.find({name: "vickey"})
{ "_id" : ObjectId("5d0226daaea0917927c50511"), "name" : "vickey", "age" : 18 }

• delete operation

delete document(delete one document that name is vickey1 that we add at create operation)

> show dbs
admin            0.000GB
config           0.000GB
local            0.000GB
self_defined_db  0.000GB
>use self_defined_db
switched to db self_defined_db
>show collections
first_table
> db.first_table.deleteOne({name: "vickey1"})
{ "acknowledged" : true, "deletedCount" : 1 }
> db.first_table.find().pretty()
{
	"_id" : ObjectId("5d02fb66f227aaf10b436011"),
	"name" : "vickey",
	"age" : 18
}

delete collection

>use self_defined_db
switched to db self_defined_db
>show collections
first_table
> db.first_table.drop()
true
> show collections      # output nothing because we had deleted the only table in collection
>

delete db(first use use dbname to switch to target db, then use delete command)

> show dbs
admin            0.000GB
config           0.000GB
local            0.000GB
self_defined_db  0.000GB
> use self_defined_db
switched to db self_defined_db
> db.dropDatabase()
{ "dropped" : "self_defined_db", "ok" : 1 }
> show dbs
admin            0.000GB
config           0.000GB
local            0.000GB

• advanced usage

more advanced usage see official docs: docs.mongodb.com/manual/crud…

user security

createuser reference: docs.mongodb.com/manual/refe…

to run mongodb security(need to auth user firstly) we should use follow command to run or restart mongod

mongod --auth --fork -f /etc/mongod.conf

mongodb does not enable access control by default, we can create a user by db.createUser(), e.g:crate a empty roles for user vickey

> use self_defined_db
switched to db self_defined_db
>db.createUser({user: "vickey", pwd: "password", roles: [ "readWrite", "dbAdmin" ]})

try to restart mongo to test auth after set roles for user

> show dbs      # output nothing because we didn't use db.auth() to auth user
> use self_defined_db
switched to db self_defined_db
> show collections
Warning: unable to run listCollections, attempting to approximate collection names by parsing connectionStatus
> db.auth("vickey", "password")
1
> show collections
test_table
> show dbs      # output dbs after auth user
test  0.000GB