DocumentDB And MongoDB

Document database, basically store the database as json.

The way that it works is you have collections which is like tables in RDBS.

You can insert a record into collections

db.getCollection("Customers").insertOne({
    text: "hello"
})

The thing is items in the collections don't need to follow a particular order unlike Cassandra. Therefore you can put in a completely different structure for example

db.getCollection("Customers").insertOne({
    name: "customer"
})

[!note]
In Cassandra, you need to define the column with the correct type like RDBS to insert a data. If you insert a data without a column, it will throw an error

When you get one item out, it will only have the fields you insert. For example for the above

db.getCollection("Customers").find({ name: "customer" })

will return

{ 
	_id: 123124910121 //some random id mongodb generated for us
	name: "customer"
}

db.getCollection("Customers").find({ text: "hello" })

{
	_id: 310230120301230230,
	text: "hello"
}