MongoDB for DBA's 1/7. Introduction. Homeworks

Homework 1.1

Download and install MongoDB from www.mongodb.org. Then run the database as a single server instance on your PC (that is, run the mongod binary). Then, run the administrative shell.

From the shell prompt type

 db.isMaster().maxBsonObjectSize

at the ">" prompt.

What do you get as a result?

 16777216

Homework 1.2

Download the file products.json from education.mongodb.com. Take a look at its content.

Now, import its contents into MongoDB, into a database called "pcat" and a collection called "products". Use the mongoimport utility to do this.

mongoimport --host localhost --port 27017 --db pcat --collection products --file "products.json" --drop

When done, run this query in the mongo shell:

db.products.find({type:"case"}).count()

What's the result?

3

Homework 1.3

At this point you should have pcat.products loaded from the previous step. You can confirm this by running in the shell:

> db.products.find()
> // or:
> db.products.count()
> // should print out "11"

Now, what query would you run to get all the products where brand equals the string “ACME”?

db.products.find({"brand": "ACME"})

Homework 1.4

How would you print out, in the shell, the name of all the products without extraneous characters or braces, sorted alphabetically, ascending? (Check all that would apply.)

db.products.find({},{name:1,_id:0}).sort({name:1})

var c = db.products.find({},{name:1,_id:0}).sort({name:1}); while( c.hasNext() ) print( c.next().name);

var c = db.products.find({}).sort({name:1}); c.forEach( function(doc){ print(doc.name) } );

var c = db.products.find({}).sort({name:-1}); while( c.hasNext() ) print( c.next().name);