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So I'm back in the shell

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and the important thing is we'll work with movies which we imported in the last course module,

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so make sure you got that data there

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and if I can quickly findOne, that already is our first read method. findOne does what the name suggests,

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it finds exactly one document, you can pass a filter to it and we learn about filters later to define

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which one document that should be

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but then it will always find the first matching document,

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if you specify nothing, it will look through all documents and simply give you back the first document

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in your collection,

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if you specified some filter, like age 30 which will not work here because we have no age field but if

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you specify something like this, it would give you the first document where this condition is met,

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so empty curly braces or no curly braces at all will simply give you back the first document.

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Please note that this also does not give you back a cursor but only one document which it instantly

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loads.

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Now this is the shape of the data in our movies collection,

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this is data about TV series and maybe we should have named it series therefore but now it's movies

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and there you see

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we've got a couple of fields, like the name, which type it is, language,

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some genres, if it's still running or already ended, the runtime when it premiered

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and well that should be all pretty self-explanatory,

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there is a bunch of data for us to play around with and that is exactly what we'll do.

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So this was findOne,

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now let's say we want to find one document but we want to find one different document. For that,

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let's first of all have a look at the alternative to findOne which is find, now find like this will

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give us back a cursor as you learned and we'll care about cursors later,

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for now let's just accept it, pretty is a method we can change to get a prettier output.

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Now this theoretically gives us all documents but since it gives us a cursor in the end, it does not

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give us all documents to avoid querying the database or a collection for all documents, in the shell,

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we just get back the first 20 documents. So with find, we see there's a bunch of stuff in there

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and for example, there is The Last Ship series and why don't we tried to find this with either find

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one or find. Well to do this,

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we will need a filter and we specify a filter on both findOne and find, it doesn't matter,

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they work in exactly the same way regarding all these options you learned about by passing a document

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to the method, so that again is the same for findOne and find, it

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doesn't matter,

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the only thing that does change of course is that findOne will give us back one document that meets

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that criteria,

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find will give us back all documents that meet that criteria.

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Now here I want to check for the name,

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so for the name field to be equal to The Last Ship, we can do this by specifying the key here, name,

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so the field where we want to look into and then the value and by default,

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if you specify it like this, so could just key value, mongodb

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will look for equality.

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So if now hit enter, we get all documents where the name is The Last Ship which happens to only be

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one document,

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we of course would get more documents if we used a field where the value would be repeating,

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so for example if we use runtime 60 by quickly changing that to runtime and then that is a number, so 60,

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then you see these are way more documents,

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obviously it's a wall of text,

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we could use pretty to make it easier to read but the main thing is these are multiple documents. Now

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that also allows me to highlight the difference with findOne, findOne only gives us back one document,

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the first document that meets that criteria which is Glee and not The Last Ship because that happens

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to be the first document

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having the right runtime. So this is findOne and find and how you pass a filter by passing a document

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as an argument and that document describes your query selector,

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so your filtering criteria you could say. Here we use equality but of course as I already mentioned, there

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are way more ways of filtering and way more operators.

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So let's dive into these operators.