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So now with our models all set up

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and with some data being added for our admin view,

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I now wanna make sure that for the front-end of our blog.

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So what our users, our visitors see,

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we of course also now use that data from the database

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with help of the models.

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And currently in the views py

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we are of course using that dummy data

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that all posts list with our dummy dictionaries.

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I will now remove that here

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or I will at least remove those dummy posts in there

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so that we can rule out that data's coming from there.

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Because now the goal

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is to step-by-step migrated those view functions

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to use the models and get the data from there.

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And let's start with the function

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which is responsible for this starting page

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where we also of course have these free block posts.

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So this starting page function here.

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There are in the past, we basically sorted all posts by date

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with that get date help or function,

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and then we got the last free posts.

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Now, of course, the goal is now to use our model,

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and therefor the first step is to import

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from the models file here in that directory,

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import the post model.

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And then in starting page, we can build a query

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as we learn it in the Shell over the last sections.

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We can reach out to our posts with post objects

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and we could get all posts with that all method here.

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We could also filter for a post if we wanted to,

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but here we don't really want to filter.

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We only have two restrictions,

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and that's a limit of posts which you wanna fetch,

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we only wanna get three posts,

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and we wanna order our posts.

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Now for ordering, we can call order by,

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we can call this on the result of filter,

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but we can also call it on the result of all

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since we can generally call it on any query set

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and all the just returns such a query set.

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So here we can also call order by

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and then pass in the key by which you wanna order.

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And that would be the date here.

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So one of the fields in our model,

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in this case, in the post model, that date field.

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I wanna filter by that and we can filter an ascending order

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or in descending order.

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And I wanna filter in descending order with a minus here

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to make sure that's the post we added the last is on top.

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Now that gives us the ordered posts,

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but we only wanna get three.

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And here's something very neat which we can do with Django,

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which we haven't seen up to this point in this course,

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which you might have done in your solution still,

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and which is absolutely correct.

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We cannot also take a slice of that result here

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with that default slicing syntax we know from Python,

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so by adding square brackets,

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and then to take only the first free elements,

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we use this slicing syntax.

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Now a couple of important annotations here though

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from my site.

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For one, you might think that this is bad for performance,

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because you could think that here Django reaches out

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to the database, gets all posts

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and then slices all posts in Python.

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And that would be very inefficient

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because we would needlessly fetch all posts

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from the database, even though we only need three,

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and then we would filter them in Python.

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So we would get way too many results from the database

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and then also have a performance hit when we filter

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or when we slice these results in Python.

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But thankfully this is not what's going on.

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Django is smart

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and it will actually convert this entire statement here

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into a SQL command.

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So it will not get all ordered posts,

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but it takes this slicing syntax also into account

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and actually creates one long query, one long SQL query

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based on this entire line where it already slices

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when fetching the data from the database.

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So it only fetches free results from the database

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because of this line.

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That's some optimization which Django does for us

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behind the scenes automatically.

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It is important to know though that for this,

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Django does not support negative indexing here.

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So -3: as we did it before

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would not be supported here.

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But that's no problem because since I'm sorting by date

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in a descending order already,

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I now wanna get the first free dates

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because since we're starting with the most recent date,

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because of the ordering, I wanna take the first three posts

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because that will be the three most recent posts.

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So therefore this one line does all they need to do,

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it gets us the free latest posts

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and therefor I can now get latest posts

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and pass them on to posts here to my starting page.

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Now, if we save that

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and we go back and reload that starting page,

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I get an error, failed to look up for key image

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in post object.

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And that makes sense because in my post model here,

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I do have a key named image name,

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that's where my image name is stored in.

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But in my template, if I have a look at the index html file

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for the starting page, there are in this template

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in the post then, in that included post,

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I am referring to just .image.

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This should now .image_name

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since that's the field name in the post model.

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And we are now working with that post model.

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So that's something we need to change and save.

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And then we can reload here.

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And this now looks way better.

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Now those posts are being loaded correctly

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and therefore let's now move on to all posts

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where of course now currently nothing is showing up

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because we haven't updated this method yet.

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In case you haven't implemented it on your own yet,

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maybe try implementing this page on your own now.

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In the next lecture, we're going to do it together again.