Basic use of Mongodb

One, cmd connection MongoDB service

Enter the bin directory of MongoDB: [d:\mongodb3.2.5\bin]$ MONGO 127.0.0.1:27017

Common query:

Show DBS View all databases

Use DbName into the current database

Show tables View collections under this database

Second, curd operation

Inquire:

1. Check all: Db.mydb2_collection.find ();

2. Query A: Db.mydb2_collection.findOne ();

Insert: Db.mydb2_collection.insert ({m:1});

Modified: Db.mydb_collection.update ({x:1},{x:999});

Delete: Db.mydb_collection.remove ({c:2});

Third, index

Pros: Can speed up all related queries
Cons: Increase disk space and reduce write performance

Index Type:

ID index: auto-created
Single-Key index:
Multi-key index: Db.mydb2_collection.insert ({x:[1,2,3,4,5]});
Composite index: When we do not know the condition of the query, we need to build a composite index
Db.mydb2_collection.ensureIndex ({x:1,y:1}); Create
Db.mydb2_collection.find ({x:1,y:2}); Use
Expiration index: 1. Index 2 that expires after a certain period of time, and the corresponding data is deleted after the index expires
Usage scenarios: Suitable for storing data that is invalidated after some time such as user login information, stored logs
How to create:
Note: The field stored in the expired index must be of the specified time type, must be a isodate or isodate array, cannot use a timestamp, or it cannot be deleted automatically.
If it is an array, it is deleted by the minimum time
Expired index is not a composite index
The deletion time is imprecise (the removal process is a process operation that the daemon does not perform once in 60 seconds, and the delete operation itself takes time) the minimum difference of 60 seconds
Full-Text indexing: Creating full-text searchable indexes on strings and string arrays
Insert data: Db.mydb2_collection.insert ({arrticle: "AA bb cc gg hh"});
Query: Db.mydb2_collection.find ({$text: {$search: "AA"}});
Db.mydb2_collection.find ({$text: {$search: "AA bb ee"}}); Multi-keyword or relationship
Db.mydb2_collection.find ({$text: {$search: "AA Bb-cc"}}); does not contain CC
Db.mydb2_collection.find ({$text: {$search: "\" aa\ "\" bb\ "\" Cc\ "}});//multi-keyword and relationship
Full-text index similarity:
Query: Db.mydb2_collection.find ({$text: {$search: "AA bb"}},{score:{$meta: "Textscore"}});
Db.mydb2_collection.find ({$text: {$search: "AA bb"}},{score:{$meta: "Textscore"}}). sort ({score:{$meta: "Textscore"} Sort

Properties of the index:
Name property
Specify the name to create the index: Db.mydb2_collection.ensureIndex ({c:1,y:1},{name: "Normal_index"});
Delete Index by name: Db.mydb2_collection.dropIndex ("Normal_index");
Uniqueness of Unique indexes:
Db.mydb2_collection.ensureIndex ({m:1,n:1},{unique:true})
Function: Do not insert if present when adding, otherwise insert
Sparsity: Sparse
Created: Db.mydb2_collection.ensureIndex ({m:1},{sparse:true});
Query Force index: db.mydb2_collection.find ({m:{$exists: false}}). Hint ("m_1");
Location Index:
2d:
Create 2d Flat index: Db.mydb_location.ensureIndex ({w: "2d"});
Location representation: Latitude [longitude, latitude]
Range of values: Longitude: [-180,180] latitude [ -90,90]
Insert: Db.mydb_location.insert ({w:[2,1]});
Near query:
Check the nearest point to []: Db.mydb_location.find ({w:{$near: []});
Search for points similar to [10]: Db.mydb_location.find ({w:{$near: [All], $maxDistance: 10}});
Shape Query $geoWithin:
Rectangle $box: Db.mydb_location.find ({w:{$geoWithin: {$box: [[0,0],[2,2]}}});
Round $center:db.mydb_location.find ({w:{$geoWithin: {$center: [[[0,0],2]}}});
Polygon $polygon:db.mydb_location.find ({w:{$geoWithin: {$polygon: [[[0,0],[2,2],[0,2]]}}});
Geonear query:
Db.runcommand ({geonear: "Mydb_location", near:[1,2],maxdistance:3,num:1});
2dsphere Index Spherical Location:

Iv. Security Mechanisms

MongoDB Security mechanism:
1. Physical separation (safest): unrealistic
2. Network isolation
3. Firewall isolation: Give fixed IP access rights
4. User name and password

Create user
Db.createuser ({User: "Jalja", pwd: "Jalja", Roles:[{role: "Useradmin", DB: "MyDB"},{role: "read", DB: "Test"}]});

Permissions: Read, ReadWrite, DbAdmin, Dbowner, useradmin

Add Auth =true enable authentication in mongo.conf

Connect using username and password: MONGO 127.0.0.1:27017-u jalja-p Jalja

The role of MongoDB
1. Database roles
2. Cluster role
3. Data Backup role
4. Other special privileges

Basic use of Mongodb