function MongoDB on the CENTOS7

Installing the service side

Yum Install Mongodb-server

Installing the Client

Yum Install MongoDB

Version
MONGO--version

Is MongoDB installed?
Which Mongod
History | grep MONGO

Mkdir-p/data/db/

Start

Mongod--dbpath=/data/db--port=27017

Off, also available for kill

Mongod--shutdown

Add log

Mongod--dbpath=/data/db--port=27017--fork--logpath=/var/log/mongod.log

View Logs

Tail-f/var/log/mongod.log

Connecting clients

Mongo

Display Database

>show DBS;

Create a database

>use Part9;

Insert Document

>db.users.insert ({"username": "Sid"});

Show collection

> Show Collections
System.indexes
Users

Querying a document in a collection
> Db.users.find ();
{"_id": ObjectId ("565468b4ac40378400147957"), "username": "Sid"}
> Db.users.insert ({"username": "Zoe", "Group": "Reporter"});
Writeresult ({"ninserted": 1})

> Db.users.insert ({"username": "Zoe", "Group": "Reporter"});
Writeresult ({"ninserted": 1})
> Db.users.find ();
{"_id": ObjectId ("565468b4ac40378400147957"), "username": "Sid"}
{"_id": ObjectId ("56546ce3ac40378400147958"), "username": "Zoe", "Group": "Reporter"}

Query number of documents
> Db.users.find (). Count ();
2
> Db.users.insert ({"username": "Zoe", "Group": "Programmer"});
Writeresult ({"ninserted": 1})
> Db.users.find ();
{"_id": ObjectId ("565468b4ac40378400147957"), "username": "Sid"}
{"_id": ObjectId ("56546ce3ac40378400147958"), "username": "Zoe", "Group": "Reporter"}
{"_id": ObjectId ("5654 6d68ac40378400147959 ")," username ":" Zoe "," Group ":" Programmer "}
> Db.users.find (). Count ();
3
> Db.users.find ({"_id": ObjectId ("56546ce3ac40378400147958")});
{"_id": ObjectId ("56546ce3ac40378400147958"), "username": "Zoe", "Group": "Reporter"}

Update the document, but only one line of the document is modified
> db.users.update ({"username": "Zoe"}, {$set: {"group": "Writer"}});
Writeresult ({"nmatched": 1, "nupserted": 0, "nmodified": 1})
> Db.users.find ();
{"_id": ObjectId ("565468b4ac40378400147957"), "username": "Sid"}
{"_id": ObjectId ("56546ce3ac40378400147958"), "username": "Zoe", "group": "Writer"}
{"_id": ObjectId ("56546d68ac40378400147959"), "username": "Zoe", "Group": "Programmer"}

Update all documents that meet the criteria, multi:true
> db.users.update ({"username": "Zoe"}, {$set: {"group": "Writer"}}, {multi:true});
Writeresult ({"nmatched": 2, "nupserted": 0, "nmodified": 1})
> Db.users.find ();
{"_id": ObjectId ("565468b4ac40378400147957"), "username": "Sid"}
{"_id": ObjectId ("56546ce3ac40378400147958"), "username": "Zoe", "group": "Writer"}
{"_id": ObjectId ("56546d68ac40378400147959"), "username": "Zoe", "group": "Writer"}

Use Save () to modify
>db.users.save ({"_id": ObjectId ("56546d68ac40378400147959"), "group": "Reporter"});

> Db.users.find ();
{"_id": ObjectId ("565468b4ac40378400147957"), "username": "Sid"}
{"_id": ObjectId ("56546ce3ac40378400147958"), "username": "Zoe", "group": "Writer"}
{"_id": ObjectId ("56546d68ac40378400147959"), "group": "Reporter"}

Update () has three parameters, save () has only one parameter, the difference between the two, note

Delete a document from the collection remove ()

First construct a collection as follows

> Db.users.find ();
{"_id": ObjectId ("565468b4ac40378400147957"), "username": "Sid"}
{"_id": ObjectId ("56546ce3ac40378400147958"), "username": "Zoe", "group": "Writer"}
{"_id": ObjectId ("56546d68ac40378400147959"), "group": "Reporter"}
{"_id": ObjectId ("56547d15ac4037840014795a"), "group": "Reporter"}
{"_id": ObjectId ("56547d18ac4037840014795b"), "group": "Reporter"}
{"_id": ObjectId ("56547d1bac4037840014795c"), "group": "Reporter"}
{"_id": ObjectId ("56547d1cac4037840014795d"), "group": "Reporter"}

5 Documents deleted

> Db.users.remove ({"Group": "Reporter"});
Writeresult ({"Nremoved": 5})
> Db.users.find ();
{"_id": ObjectId ("565468b4ac40378400147957"), "username": "Sid"}
{"_id": ObjectId ("56546ce3ac40378400147958"), "username": "Zoe", "group": "Writer"}

Re-construct a collection

> Db.users.find ();
{"_id": ObjectId ("565468b4ac40378400147957"), "username": "Sid"}
{"_id": ObjectId ("56546ce3ac40378400147958"), "username": "Zoe", "group": "Writer"}
{"_id": ObjectId ("56547e2bac4037840014795e"), "group": "Reporter"}
{"_id": ObjectId ("56547e2dac4037840014795f"), "group": "Reporter"}
{"_id": ObjectId ("56547e2fac40378400147960"), "group": "Reporter"}
{"_id": ObjectId ("56547e30ac40378400147961"), "group": "Reporter"}

Add the second parameter in remove () to delete only the first document in the collection that satisfies the condition

> Db.users.remove ({"Group": "Reporter"}, true);
Writeresult ({"nremoved": 1})

Delete all the documents

> Db.users.remove ({});
Writeresult ({"Nremoved": 5})
> Db.users.find ();

Delete all documents and indexes in the collection

> Db.users.drop ();
True

function MongoDB on the CENTOS7