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Now sorting is one thing we can do,

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we can also skip a certain amount of elements.

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Now why would you skip?

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Let's say in your client application, a website, you implement some pagination, so people can view the

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results which are distributed across multiple pages because you don't want to have one page with 100

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results but you want to have 10 on every page.

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Now if the user switches to page number two, you want to skip the first 10 results which would have been

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on page number one but now you want to display the results for page number two

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and therefore, you can add a skip method here to skip results.

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So let's save and add skip ten here, you will see that the results here are slightly different,

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we got 6.6 ratings

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if you remember previously in the same amount of documents, we had 6.4 and so on,

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so it looks like we skipped some documents and indeed we did.

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So skipping does allow us to move through our data set,

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if I skip 100, then we can see the ratings are much higher because we skipped all the bad ones, the 100

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bad ones, we skipped them,

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now skip is also used on a cursor as you can tell. Now related to skip somehow is the limit function, limit

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allows you to limit the amount of elements the cursor should retrieve at a time

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and that also means the amount of documents you can then move through with a cursor.

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You can limit this to 10 for example,

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the interesting thing is if you here add count, you still have 240

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but if I now execute pretty here, indeed the cursor is not fully exhausted but I only get 10 elements

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with the help of limit,

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so limit also allows us to retrieve a certain amount of documents but only the amount of documents we

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specify.

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This also is related to pagination,

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if you had your website with 10 products per page, it doesn't suffice to skip 10 products because you're

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on page number two,

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you also only want to display 10 products on page number two and that is exactly what limit helps you

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do,

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it limits the amount of data that is retrieved and returned through the cursor.

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Now there is maybe one thing which you thought about,

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if we have this query where we sort and I do actually sort twice here, I didn't notice that, as you see

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it didn't do any harm but of course it is redundant,

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so if we have a query where we sort and then we skip and then we limit, does the order matter?

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In theory you would say it should matter right

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because if I skip before I sort, then I skip on the unsorted documents,

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so I simply skip the first 100 in the collection and I only sort the remaining ones which means I don't

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necessarily skip the badly rated ones but I simply skipped some random items and I only sort after

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skipping

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which of course is typically not what you want.

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Now the good thing is on a cursor, the order here does not matter,

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later in the aggregation framework, this will change and I will talk about it there but here, you can

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have skip, sort and limit in whichever order you want.

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You can limit first, you can skip first,

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mongodb and the cursor will automatically do it in the right order,

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it will sort first, then skip and then limit.