Mangodb simple to use

One 、 brief introduction

1、 Data model ：

  At the same time, some scripts can be used for logical processing

2、 characteristic

• High performance
• High availability
• High expansion
• Rich query methods
• Modeless , The data structure is relatively loose （BSON Storage ）

3、 Related contents of the configuration file

# mongod.conf

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

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

# Where and how to store data.  Data storage location 
storage:
  dbPath: /var/lib/mongo
  journal:
    enabled: true
#  engine:
#  wiredTiger:

# how the process runs  Background operation 
processManagement:
  fork: true  # fork and run in background
  pidFilePath: /var/run/mongodb/mongod.pid  # location of pidfile
  # timeZoneInfo: /usr/share/zoneinfo

# network interfaces  The binding of IP  and   port   Bind lan IP
net:
  port: 27017
  bindIp: 127.0.0.1  # Enter 0.0.0.0,:: to bind to all IPv4 and IPv6 addresses or, alternatively, use the net.bindIpAll setting.


#security:

#operationProfiling:

#replication:

#sharding:

## Enterprise-Only Options

#auditLog:

#snmp:

Two 、 Basic operation

1、 Database creation and deletion

Create database ：use dbname, It should be noted that , Databases without collections exist only in memory .

Delete database ：db.dropDataBase()

2、 The basic operation of a set

stay mangobd in , Set is equivalent to the table structure of relational database . Creation is divided into implicit 、 Create explicitly .

Explicit creation is to create a table without data , Implicit creation is to directly create a table when inserting data .

• Single insert ：db.comment.insert({"id":"1","content":" test "})
• Batch insert ：db.comment.insertMany([{"id":"2","content":" test 2","f":"123"},{"id":"3","content":" test 3","y":"123"}]), When the insertion fails , have access to try{}catch{}
• Query all ：db. aggregate .find()
• Conditions of the query ：db. aggregate .find({"id":"123"})
• Look up a ：db. aggregate .findOne( Conditions )
• Projection query ：db. aggregate .find({"id":"123"}, {"content":1, "id":0})
• to update ：db. aggregate .update(query,update,options)
  • Covering the update ：db.comment.update({id:"1"}, {f:NumberInt(2)})
  • Partial update ：db.comment.update({id:"2"}, {$set:{f:NumberInt(3)}})
  • Batch update ：db.comment.update({id:"2"}, {$set:{f:NumberInt(3)}}, {multi:ture})
  • Column value growth ：db.comment.update({id:"2"}, {$inc:{f:NumberInt(1)}})
• Delete ：db. aggregate .remove( Conditions )
• Statistics query ：db. aggregate .count( Conditions )
• Paging query ：db. aggregate .find().skip(2).limit(2), Second page each page 2 That's ok skip from 0 How many bars start jumping
• Sort query ：db. aggregate .find().sort({ Field :1}),1 Ascending 、-1 Descending
• Regular expression queries ：db.comment.find({content:/2/})
• Comparison query ：db. aggregate .find({ Field :{$gt:700}})
• Contains the query ：db. aggregate .fund({ Field :{$in:[v1,v2]}})
• Conditions of the query ：$and、$or,db.comment.find({$and:[{f:{$gt:2}}, {id:{$gt:2}}]})

3、 Indexes -Index

Index is to improve efficiency , Full set scan without index .mongoDB When index is used B-Tree.

Type of index ：

• Single field index ： Add an index to a field
• Composite index ： Index of multiple fields
• Other indexes ： Geospatial index 、 Text index 、 Hash index

Index management

• see ：db. aggregate .getIndexes()
• establish ：db. aggregate .createIndex(keys, options),keys Is to add an indexed field ,options as follows
• remove ：
  • db. aggregate .dropIndex( The index name \ Conditions )：db.comment.dropIndex({content:-1})
  • Delete all indexes ：db.comment.dropIndexs()

Implementation plan ：

Used to analyze the execution performance of query statements .db.comment.find({f:2}).explain(), Use Compass Check more clearly ：

After adding the index ：

Cover queries ： When the query condition and query projection only contain index fields , Return results directly from the index , It's very efficient .