Mongo DB is document based data based. Document is just self-contained chunk of information. We can group many documents into collection and many collections into DB.
So in Mongo database is a set of collection, and a collection is a set of documents. One great advantage of document database is mapping of the program objects into the database entities, it is easier.
In order to install mongoDB, got to their download page and follow their instruction.
In order to start the server we can run the following. <dataLocation> is the directory that we want to contain the mongoDb data
From the location of the mongod, or if the mongo binary in the path.
mongo server run on port 27017.
Mongo database store the information in binary JSON format called BSON.
BSON format has some features like:
- length prefix for every field – that help to save time when doing i/o to the disk, if we don’t need the field, then when know to where more the file pointer.
- support additional primitive that are not supported in JSON like UTC Date. Also the type of every field is stored with the field.
In order to start mongo REPL, we need to run mongo client, we cam do this by running:
mongo 2016-10-26T20:11:06.574+0300 I CONTROL [main] Hotfix KB2731284 or later update is installed, no need to zero-out data files MongoDB shell version: 3.2.10 connecting to: test Welcome to the MongoDB shell. For interactive help, type "help". For more comprehensive documentation, see http://docs.mongodb.org/ Questions? Try the support group http://groups.google.com/group/mongodb-user >
Once we start the mongo client, we get the REPL (read, evaluate, print, loop) and we can start running commands.
The first command that we run is
db, this command will tell us the out current used db.
The second command is
use <dataBaseName> will switch to the database dataBaseName.
In the below example we will run db, to check the database and then change the database to check.
C:\Program Files\MongoDB\Server\3.2\bin>mongo 2016-10-26T20:21:49.955+0300 I CONTROL [main] Hotfix KB2731284 or later update is installed, no need to zero-out data files MongoDB shell version: 3.2.10 connecting to: test > db; test > use check; switched to db check > db check >