Database-mongodb-Common Commands

command to start the database

1	mongod --dbpath C:\MongoDb\data\db -logpath C:\MongoDB\data\log\mongolog.log

Common commands for several databases

 
   
  

  
    
   
use DATABASE_NAME // 创建数据库
 
   
  

 
   
  

  
    
   
>db // 检查当前的数据库
  
    
   
mydb
 
   
  

 
   
  

  
    
   
>show dbs // 查询数据库列表
  
    
   
local 0.78125GB
  
    
   
test 0.23012GB
 
   
  

 
   
  

  
    
   
db.dropDatabase(‘mydb‘)
 
   
  

Create a collectionMongoDB's db.createcollection (name, options)used to create a collection
  nameis the name of the collection to create Optionsis a document that specifies the configuration of the collection

capped	boolean	(optional) If true, it enables the upper bound collection. The upper bound collection is a fixed-size collection that automatically overwrites the oldest entries when it reaches its maximum size.   If you specify true, you also need to specify the size of the parameter.
autoindexid	boolean	(optional) If true, the index _id field is created automatically. The default value is False.
size	number	(optional) specifies the maximum size of the upper collection byte. If capped is true, you also need to specify this field.
Max	Number	Optionally, specify the maximum number of files allowed for the upper bound collection.

Show All Collections

 
   
  

  
    
   
show collections
 
   
  

 
   
  

  
    
   
>db.mycol.find()
 
   
  

 
   
  

  
    
   
>db.mycol.find().pretty()
 
   
  

Delete Collection

DB.collection_name.Drop()

the RDBMS WHERE clause is equivalent to MongoDBConditional query

 
   
  

  
    
   
db.mycol.find({‘age‘:{$gte:20}}).pretty()
 
   
  

Mainly the usage of several keywords < $lt <= $lte > $gt >= $gte = Do not write! =!! = $ne








From for notes (Wiz)

Database-mongodb-Common Commands