Lesson video

Hello, and welcome to lesson three in our flat-file databases unit.

I'm Andy, and in this lesson, we're going to be finding information by searching a database.

For this lesson, you'll need the cards that you made in the first lesson.

You'll also need to be able to access a website, and you could do with a pen and paper to jot some things down on.

Other than that, please clear away any distractions, and then we can start.

In this lesson, you'll see how grouping then sorting data allows us to answer questions.

You'll be able to explain how information can be grouped.

You'll group information to answer questions.

And you'll also combine grouping and sorting to answer more specific questions.

We're just going to think for a moment as to why do we use computer databases.

See if you can think of good reasons why we use them and how they help us.

I'll give you a moment to think.

Okay.

There's lots and lots of reasons.

It might be because they're fast.

We did some sorting last lesson, and it sorted things really quickly.

We can easily add information to it.

We can easily share it.

The ones you've been looking at that on the internet, anybody anywhere in the world could see them.

Okay? There's a whole host of reasons why we might use them.

And those are just a few.

I'm sure show you thought of others.

So we need to go back to the record cards that you made in lesson one.

And what I'd like you to do is carefully cut off the corners.

So on everywhere there isn't a tick, okay, so only where there isn't a tick, you'll need to carefully cut the corners off.

Okay? Leaving only the corns with ticks on them.

It means that once we have just those corners left, we can use that to group our data.

And I'll show you how that works now.

Okay, so I'll just do one of these cards.

So here's my card.

I need to cut off this corner and this corner.

So I've got my scissors here.

And if I've very carefully cut, I can remove that corner.

And I just need to turn this a little bit, and remove this corner.

That's it.

That's gone.

I don't need those.

And there, you can see my cards.

And here's all the rest of my cards.

All I'm left with is the ticks.

So if I put my cards together, okay? You can see.

I can see the corners, some have been cut off and some haven't, and it means that I can sort my information quite quickly.

I can group it.

So for example, we've got, "Has it got six legs?" If I get that corner, just the very, very corner, and I shake it, okay? I'm left with one.

There's only one that's got six legs in my pile, and it's the wasp.

So I can put these back together.

And we can just try a different one.

So we've got, "Can it fly?" So if I grab that "Can it fly corner?" corner, and I just grab the very, very corner there.

And if I shake it, I get left with the two that can fly, the wasp and the bat.

Okay? So that's going to be your task.

So you need to very carefully cut off the corners that don't have ticks, and then try asking yourself some of the questions and hold the corners, shake them out, and see how many you get left with.

So pause the video now.

Okay, so I'll just try answering those questions with my database.

Your answers might be different from mine, because you used different creatures.

You picked the creatures yourself.

So here's my cards.

And the first one is, "How many half six legs?" So I need to carefully choose the six legs corner.

And if I shake it out, that's it.

I've just got one, and it's the wasp.

Okay, so the next one is, "Which ones can fly?" So how many can fly? Put them back together.

And if I grab this corner, the "Can fly" corner.

Make sure they're all together.

Grab that corner, shake them out, and there we are.

We've got the bat and the wasps can fly.

And these are the missing corners, can't fly.

And how many are more than one colour? So let's just stack all those together again.

And "Is more than one colour" is here.

So if I grab that corner, and shake it out, okay? So there's the ones that aren't, and these ones all have this corner.

There we are.

There's one, two, three, four, five, six of my eight are more than one colour.

Okay, I hope you managed to make that work with your database.

Okay, so let's just think about what we've just done.

We've got a few questions to ponder.

So the first question is, how reliable do you think that method is? Okay? It seemed to work fairly well.

I had to be very careful just to get the very corners.

I think if I grabbed a little bit too much, I might've got more cards than I should have done, held onto.

How did it compare with grouping in lesson one? Okay, grouping your lesson one, you looked through each card.

So I think it was quicker.

I think it was quite a bit quicker, because we could just get the right corner, and that would do it for us.

Okay? Which do you think is better? Well, I think on balance, grabbing the corners is probably the quicker method, so it's probably the better method.

We just have to be careful we've made our cards properly, carefully.

So what about if we had lots of records.

So what happens if we had 2000 records? That'd be 2000 cards.

Do you think that method would still work? Okay.

I don't.

I don't think we could even pick them up with one hand, let alone shake them out, and reliably end up with the ones that we wanted.

So what we're going to do now, is we're actually going to search the computer database.

Okay? And one of our first things we're going to try, is we're going to use a database of different countries, and we want to find out which countries in the database are German speaking.

So this is what it will look like.

And you can see it's got language, German.

So it's picked out three.

It's picked out Germany, Austria, and Switzerland.

Okay, so here's the database we're going to be using.

There's a link in the worksheet for you, so you can find that shortly.

And our question was, which countries are German speaking? So what we need to do, you can see here, these are all our record cards, or we can see in table view.

It doesn't matter which one we choose.

And it says search here.

I need to click on this little magnifying glass.

And then I can make some choices.

And I'm going to choose language equals, and I can choose the language, which is German.

And there we go.

I can see I've got one, two, three results.

Okay? So we click on the magnifying glass, and then we choose what we want to search by.

And then we need to search what we're searching for.

Okay, so in the worksheet, there's a link to the countries database, and you need to open that, and try searching to answer the questions.

So pause the video now.

Okay, so let's look at those questions together then.

So the first one is, which countries in a database use the Euro as currency? So in the search, I need to go to currency, and the value should be the Euro.

And it tells me there's seven.

And the seven are France, Spain, Germany, Italy, Greece, Austria, and Belgium.

The next question is, which two countries are Chinese-speaking? I can just change the search, or I can clear it first.

It's okay either way.

So that clears it.

And I want the language, is, and the language should be, and it tells me two, so already I know it's two, but which two are they? And it's China and the territory of Hong Kong.

So that's the two Chinese speaking areas.

The next one is, which country has a population of 8,800,000? So I can go and choose population, and the population should be, I need to look down this list quite carefully.

And there it is.

And it tells me it's Austria.

Okay? And the last question is, which countries have a population of over 100 million? So I just cleared the search.

We'll do this one from scratch.

So population, and it needs to be, rather than equal to, it needs to be more than 100 million.

So this is the greater than sign.

And in value, there's actually a big, long list, and it's quite hard to pick the right one.

I can actually type in here, so if I type in the 100 million, and then search, okay, it turns up the populations of Russia, United States, China, Brazil, India, and Japan, all have populations of over 100 million people.

Okay, so if we want to find out things in a slightly more refined way, we can actually combine the tools.

So we can group and then sort data.

So if I want to find out the German speaking country with the smallest population, I can do that.

First of all, I need to search the database, and you can see it's been searched for the language as German, so that's German speaking.

And then can you see how the results have been sorted? If you look carefully, the population has been sorted from smallest to biggest.

So the smallest German speaking country is Switzerland.

So let's have a look at that in the database itself.

Okay, so let's just work through that.

So we want a German speaking country with the smallest population.

So I need to go to search, and I need to search for language, and the language needs to be German.

So that then just pulls out the three that we need.

So that's a bit like shaking the cards, when we grabbed the corner.

What we can then do, is we can click on any of these headings, and we can sort it from smallest to biggest, or biggest to smallest, and so on.

So that's already sorted there.

Smallest to largest, and you can say Switzerland is the smallest German speaking country in the database.

So your task now is to do that with some questions on the worksheet.

You need to group and then sort data to answer the questions that have been given.

So please pause the video now.

Okay, so let's work through the questions on the worksheet together.

Let's see how you did.

So the first question was, which German speaking country has the largest population? So I need to search for German speaking.

Language is German.

And it's the largest population.

So I could sort it either way, but if I sort it from biggest to smallest, the largest population, German speaking, not surprisingly, is Germany.

The next question is, which Chinese speaking country has the smallest population? So I need to go back to language, and I need to search for the language as Chinese.

And it's the smallest population.

I've only got two.

If I wanted to sort it, I could.

The smallest at the top, and it's Hong Kong.

Next question is, which country using the Euro currency has the smallest area? So again, I'm going to clear the search, and I need to do currency, and it's Euro, and I need to know the smallest area.

So that's the land area.

So if I click on that, we're going from smallest to largest.

And Belgium is the country with the smallest land area that uses the Euro in this database.

So that one was Belgium.

And it says, which one has the smallest population? So it's the same currency question, uses the Euro currency, has the smallest population.

So click on population instead.

And there we have it.

Austria has the smallest population of countries that use the Euro in this database.

And then the last one, out of all of the countries with the population over 100 million, which has the largest area? This one needs a bit more thinking about.

So we need to pick out population greater than 100 million.

So if you remember, we keyed that in before.

So that's our search, population of over 100 million, and which is the largest area? So if we go and click on area, and you can see smallest to largest, largest to smallest, Russia is the largest country and land area with a population of over a hundred million, and it's land area's 17 over 17 million square kilometres.

Okay, just before we finish, we're just going to think about data accuracy, how precise, how right is the data? Actually in the database itself, there is an error, there is a problem.

If we look in the populations, it shows Mexico, and Mexico is quite a big country in terms of the area it has, but it says its population is 56,000 people, and countries with much smaller areas have much bigger populations.

While that can be true, this data's actually wrong, and we can check it by looking at encyclopaedias or checking online.

Why do you think that might have happened? Why do you think there could be an error? I'll give you a moment to think.

Okay.

There's a few possible reasons, but the most likely is somebody actually typed in wrongly.

The most common error is actually people putting the data in wrong in the first place.

So somebody's probably pressed the wrong key, or they haven't put some zeros on the end that should be there.

So in this lesson, you've grouped records in a paper database, and also in a computer database, you've combined search and order to answer questions.

So that's it for this lesson.

If you'd like to share your work, please ask a parent or carer to share your work for you.

It can be shared on Instagram, Facebook, or Twitter, tagging it with @OakNational, and #LearnWithOak.

See you next time.