MONGODB CREATE DATABASE and collection commands db.createcollection detailed

Switch/CREATE Database

Use Yourdb; The current database is created automatically when a collection (table) is created

The complete command is as follows:
Db.createcollection (name, {capped: <boolean>, Autoindexid: <boolean>, size: <number>, Max <number })

Name: Collection of names
Capped: Whether to enable the collection limit, if you need to set a constraint, default is not enabled, this parameter does not make sense
Size: Limits the amount of space used by the collection, which is not limited by default
Max: Limit of maximum number of bars in the collection, defaults to No limit
AUTOINDEXID: Whether to use _id as the index, by default (TRUE or FALSE)
Size has a higher priority than max

Common methods introduced:
1, in general, we create a collection with Db.createcollection (name), such as: Db.createcollection ("Log"), create a collection named log, without any size, quantity limit, using _id as the default index;

2. Limit the size of the collection space: Db.createcollection ("Log", {size:1024}) or db.createcollection ("log", {capped:true,size:1024}), Create a name for the log collection, limit its space size is 1M, if it exceeds the size of 1M, it will delete the oldest record;
3, limit the maximum number of sets: Db.createcollection ("Log", {max:1024}), create a name for the log collection, the maximum number of bars is 1024, more than 1024 and then insert the data will delete the oldest record. This can not use Capped:true, or will error;
4, that is, limit the maximum number of bars to use space size: db.createcollection ("Log", {size:1024,max:1024}) or db.createcollection ("log", {capped:true,size : 1024,max:1024}), limit collection maximum usage space is 1M, maximum number of bars is 1024

The above is a reference to the official documents and the actual test results, you can also see that the capped parameter is not useful, use not all can.

a detailed description of MongoDB : please click here
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Related reading :

MongoDB Backup and Recovery http://www.linuxidc.com/Linux/2012-07/64113.htm

CentOS Compile Install MongoDB http://www.linuxidc.com/Linux/2012-02/53834.htm

CentOS compilation installs MongoDB with MongoDB PHP extension http://www.linuxidc.com/Linux/2012-02/53833.htm

CentOS 6 uses Yum to install MongoDB and server-side configuration http://www.linuxidc.com/Linux/2012-08/68196.htm

Ubuntu 13.04 under Install MongoDB2.4.3 http://www.linuxidc.com/Linux/2013-05/84227.htm

How to create a new database and collection in MongoDB http://www.linuxidc.com/Linux/2013-06/85749.htm

MongoDB entry must read (both concept and actual combat) http://www.linuxidc.com/Linux/2013-07/87105.htm

The MongoDB authoritative guide (mongodb:the definitive) English language version [PDF] Http://www.linuxidc.com/Linux/2012-07/66735.htm

MONGODB CREATE DATABASE and collection commands db.createcollection detailed (GO)