Creation & Insertion in MongoDB

creation and insertion in MongoDB. We know that MongoDB is a document-oriented database

So a collection will be containing multiple documents. So at first we shall concentrate on the

collection creation, then we shall concentrate on the document creation. So at first we are

considering the collection creation. To create a collection in the MongoDB, we can use the method

there is a create collection method. So, syntax will be db.d. Create collection. Here we're having

some name and then some options. So, let now let us discuss what is the name and what is

option. The name is the string type value and for the second argument, we can specify

some options. And these options are used to control the documents inside the collection

So, this is where mentioning the collection name and some options will be there

Now, let us discuss that what are the different options are available there

So, let me repeat once. So, db.crete collection is a method. At first we shall be passing the collection name and some options will be there So the options are like this So first one is a capped So cap is a field and the its type is bullion and it is optional if it is true

then enables the capped collection. Now what is the capped collection? So capd collection is a fixed

size collection. That means we are supposed to mention the size of the collection. So to make that

one, I shall have to make capped. That is a bullion option should be made true. The next field is

auto index ID. It is of the type of bullion. If this auto index ID, if it is true, then

automatically create index on underscore ID field's default value is false. So, its default value is

false, but if I want to make that one true, then the auto index ID will get created on this

underscore ID. Next one is the size and it is of the type of number. So, it is optional, specifies

a maximum size in bytes for a capped collection. So, when this capped, this bullion option is true

then this particular size will be working there Next one is the max So it is a number it is optional specifies the maximum number of documents allowed So these are the options that are available for the collection creation

Now let us discuss how to create one document. So document insert, so to insert documents in the collection, we have to use the insert method

Now what is the syntax? syntax is db. Collection name, dot, insert and then document

So, the documents should be in the JSON format. I think to know it better, to understand it better, let us go for one practical demonstration

where you will be issuing such commands and we shall show you that how the outputs are coming

So, here is the demonstration for you. So at first we are opening one terminal, so control alter T, we are issuing

command pseudo service mongo db start password is asked password is given then I shall issue

the command mongo to get the mongo shell so the mongo shell has been obtained so going for creation of our database so I shall go for show DBS you see the database is not pre so I going for my database so

switch to my database so now if I go for D B I can see that I'm working with this

my database here but if I go for the DBS show DBS I'm finding that my

database is not coming in the list because this my database is having no collection so let us insert one collection here

under this my database okay so in the case what we shall do we shall create a

collection whose size is 5 mb and it can store 100 documents maximum so how

to do that one so db. create create collection the name of the collection is

name of the document is employee this the collection is there so here the name of the

collection is employee and then we shall go for the size so as I have mentioned

it will be 5 mb so 5 to 4 to 880 and if it will have