CSEC IT Night before the exam CRASH COURSE

Added: 2026-05-15

[00:00:00]Um, yeah, I can't count the amount of times that people message and say they wanted a free crash course. And well, I'm really tired. So, there's no way I able to stay up for another 4 hours trying to teach the whole of CC IT. So, here's a free 4-hour video that goes through verification and validation, spreadsheets, databases, and algorithm.

[00:00:25]All of the hardest topics in CC IT.

[00:00:28]Hopefully, you learned something.

[00:00:30]You're welcome. Don't forget to come back later to see the solutions as if I get the paper. But yeah, I didn't want to spend more than 30 seconds talking about it. So, here you go. Watch. No memes, no nothing. Just straight crash cushing. It's stuff that I covered in the past four weeks if you didn't know. Yeah. Bye.

[00:00:52]In the most nonchalant way ever.

[00:01:00]How long I have? I have about I had to finish this by 7 o'clock. So I have 10 minutes. All right. You all ready? All right. So I need you I need youall to participate in the chat and when I ask a question you will have to like answer so that it will make life a little easier for us when we go through it. Right.

[00:01:13]Okay. So with verification and validation there are two major things that we need to know.

[00:01:30]Um data data is broken down into um like raw facts and figures and what right? But data needs to have something called integrity.

[00:01:49]Integrity means that it is um trusted.

[00:01:56]It is correct.

[00:01:59]It is like yeah trusted and correct correct/ error-free.

[00:02:07]So you don't want to you don't want to have data and the data is wrong cuz that would make sense. So, for example, if you have like a um if you have a if you have a a database with people's email addresses and you have the wrong email address, then when you try to send emails to the people, guess what? They won't get the emails because you have the wrong email address. So, the data should be trusted. That means it's correct and errorree, right? In order for the data to be trusted and and error-free, you have to make sure that the data doesn't have any errors. And in order for it to not have any errors, it must be val verified and validated.

[00:02:58]So I started verified first, right? So verified means that whatever it's supposed to be whatever wherever you want it to be, it's exactly what it's supposed to be.

[00:03:09]So this is exactly as or this is our exact copy.

[00:03:19]So for example, if somebody write down their ID number and they put 1 2 6 3, there's a problem here because this doesn't look like a one. This looks like a seven. If they really wanted it to be a one, they're supposed to put a one under underneath like that. So some people write their names and it's hard to follow. So if you if you write your name in cursive and you're like your name is Ilana, right? Somebody who's taking this information and trying to put it into a computer will have a problem because they don't understand what what this is.

[00:03:52]They don't know if this is a L. They don't know if it's a I. They don't know if it's a whatever. That's a that has a problem with the with the name. So in order for it to be verified, you need to make sure that you you have some certain checks in place, right? So there are two ways that data could go in wrong. The two ways that could go in wrong is transcription.

[00:04:13]Transcription is when your writing is like that, like literally trash. But hard to make sense of it. It's so it's so difficult to make sense of it that you can't put it into the computer anymore because it just it just doesn't make sense. You can't your car um effectively put it in. In order to fix the transcription, you'll make them put it in in block letters. So it'll have to be I L L E A N A. This makes it a lot easier for you to understand that the person's name. So that's why you ask them to do it in block letters. If you ask them to put in block letters, you'll fix the transcription problem. The next type of problem that you could have is transposition.

[00:04:54]Transposition is when people mix up numbers. So let's say you have to write 20 26. Instead of writing 2026, you end up writing 2062.

[00:05:04]Now, some people call this like dyslexic. So, sometimes people might be dyslexic and they might write the wrong numbers in the other way. That is a transposition error. So, you could be trying to put in the date today, but you end up putting the wrong the wrong numbers. And that's the two types of errors that happen. So, in order to make sure data is verified, there are two ways that you make sure data is verified. you do a double entry check which means make them write it out twice. If somebody writes their information twice and it matches then it's correct. So if you tell me to write the um to give to give your password and your password is Bob 1 2 3 then you write then you put the password in the second time you put Bob one two three. That's a problem because it'll be a double entry mistake because these two are not matching.

[00:05:55]Y'all following me there in the chat?

[00:06:01]Double entry. That's the first mistake.

[00:06:03]That's the first way that you could make sure things are verified.

[00:06:07]Right?

[00:06:09]So double entry is one.

[00:06:12]The second one, sorry.

[00:06:16]The second way that you could make sure something is verified is you could do a visual check.

[00:06:26]So, somebody will fill out something on a piece of paper like this.

[00:06:32]You fill out the stuff in the piece of paper and then you put it into the computer. Before you click enter, before you click the the red button on this computer, you will go back and you look at it again to make sure everything that you intentionally wanted to put inside is actually on the screen. And the visual check will now confirm that yeah, this is exactly what it was. So when you go and fill out a form, they will usually give you back the form and be like, please verify that all of your um information is correct. Right?

[00:07:05]So the visual check is to make sure that you don't have any of these errors. The two types of errors that you could have will be transcription and transposition.

[00:07:17]Any transcription error and any transposition error, they will be picked up by double entry or visual check.

[00:07:25]Do you understand everybody in the chat? You understand?

[00:07:35]All right.

[00:07:36]Um, person in the chat that asks about Cape Kai and IT unit revision. All of that inside the learn app. Just go and download the app. There's like everything all the revision inside there. And most likely the night before the exam, I'll do some revision. But when they do a cape when they do a cape revision only five people has come. So doesn't really make any sense. So just download the app. That will save you like everything you need is inside it.

[00:07:59]Right. All right. So we're good there.

[00:08:01]So everybody understand why you have to do verification. The reason we verifying things is to ensure that we avoid two types of errors. Transcription errors, transposition errors. How do we verify things? We verify things by doing double entry and visual checks. Visual checks and double entry checks will pick up all of the double entry error, all of the um the transcription and transposition errors and therefore our data will have integrity but has only half of the integrity. Right? Everybody admit so far, right? The goal is to get to data integrity.

[00:08:37]If you all don't reply in the chat, then I don't know that you're learning cuz you're not teaching us work. The class has to respond. If the class didn't respond, then you know it's kind of send um send this color emoji in in the in the um in the chat.

[00:08:53]Yeah.

[00:08:55]All you all you got to do is send this emoji and I good.

[00:08:59]Once I see that I know learning taking place right we don't need words we don't need words right so integrity of data is going to follow verification so verified so you might see verified or you might see verification so a verification check could be double entry or visual.

[00:09:32]So that's one and two. Right? Now after you do the verification, now we had to move across to validation. So validated means a validation check.

[00:09:43]Validation check. Now the goal of validation is to try to make sure everything follows the rules.

[00:09:54]So validation to make sure that it follows the rules. What rules do we have to follow to make sure that the data is correct? So validation checks they are broken down into five. I think the syllabus wants you to do right. The first one is range.

[00:10:12]So I'll put this in a different color.

[00:10:14]So in order for data to be validated you could do a range check.

[00:10:20]You could do a um format check format slashlength consistency um reasonleness. this and I can't really pick one data type check.

[00:11:01]All right, so remember the goal of all of this is to get to what? Data integrity. So, we already passed the point where we make sure it's verified.

[00:11:10]Whatever the person intended to put in, they did put in. And we do the double entry. We did the visual to check to see if that is what they intended to put in.

[00:11:18]Now, we have to check to see if what they put in follows the rules. That's the most important part. Does it follow the rules? So, for a range check, you want to make sure that the number is within a particular range. So you say for example age for teenager must be 13 to 19. So in this little box here where they have to put in the age for teenager there's a little box here.

[00:11:47]If the person types in um 17 it will be like yes acceptable.

[00:11:54]However, if the person types in 23, it will get it'll give you a red box like that. And you ever see like a red line, a red box come around like a field when you're filling out something on the internet? Like if you fill out something on the internet and you put in the wrong email address, you ever see like a red box and the form tell you can't submit it. Like you cannot submit this form, please go back and fix this error.

[00:12:17]That is a validation check that took place. So range check basically means a number must be within a particular range and when you try to put the information into the field it will not be accepted because you could program the computer to make sure that it goes in properly.

[00:12:32]That way if you're if you have like an application that's supposed to only be for teenagers then only teenage teenagers will be able to get in. Right?

[00:12:40]So, if you if you was playing Roblox at age um at age seven and you put in your age as seven in the Roblox app, it will be like no. But if you put your age as 13, it will accept you. So, you follow the the follow the validation rules and your name was your number was within your range. Right?

[00:13:02]Next check is a format and length check.

[00:13:04]Format a link check will be example day month year or month day year.

[00:13:17]Some forms require to fill out the fill out the date like this. So you will put in the date as okay you were born on the 28th of February 9, 2014.

[00:13:33]That is acceptable, right?

[00:13:41]Or you could be born on the 29th of let's say you're born on the um not February, let's say the 31st of August or whatever one is. That's acceptable.

[00:13:52]But if you make the mistake and put this the other way around, 0931/204, they will give you an error because they're looking for the day here.

[00:14:07]No. Yeah, they will they'll put like that. Yeah, they will they will be like, oh, the day is acceptable and the month is acceptable. So good. But if you put in 09 31 2014 here, there will be a problem because they will be like, "Hold on, we have a problem." Because there is no month that has 31 inside of it.

[00:14:31]So you have to fill out the information based on the format that they want you to fill it out in. So the easiest example for that is a date. When they give you the date to fill out a particular way, you have to fill it out a particular way. Y'all understand?

[00:14:44]That is our format and length check.

[00:14:48]Next check is a consistency check.

[00:14:51]Consistency check will be an example of two fields. So let's say I have an example of one field says that you are 18 but your birthday is the first of the first um let's say that I'll put 10 or let's say that you're 11. Yeah. Let's say that you put your age in as 11 but your birthday is the 1st of the 1st 2016.

[00:15:21]according to this birthday you are actually 10 years old but your age saying that you're 11. So now it's going to be like oops there's a problem there's a consistency issue there right you'll get so this is age this is data birth so with consistency you have to compare two things when you compare those two things then you're going to be like um there's a problem there could also be other consistency issues consistency issues could be like um let's say your bank account says that you have um $100.

[00:16:02]So, this is your account and then you want to withdraw.

[00:16:07]The withdrawal amount that you put inside is $200.

[00:16:12]The ATM machine going to be like I tell you this crazy normal normal normal normal normal Yeah, the ATM machine going to be like, uh, you have been denied because that's a consistency check, right? Next check is a reasonleness check.

[00:16:42]Reasonableness check is a little hard to um to go through but reasonleness check is example um how many cars do you have and in the box for how many cars you put in 1,000 cars the system will probably be like um uh be like, uh, I think you're putting the wrong number there for the amount of cards. Right? So, a reasonable check basically will flag it and say, um, yeah, a problem, right? Then the last one, which is the most important one, which is a data type check. A data type check now is going to check to make sure that you follow the rules of the data.

[00:17:31]So, for example, a password.

[00:17:35]A password is supposed to have a capital letter P, uh, common letter A, S, S S, W, R, D, uh, number one, and a special character exclamation mark. This meets the criteria of the data type check because it meets the criteria for the password.

[00:17:56]However, if you put in the password and you put password one, you'll get a red box around it because you are missing um two of the types of data that they they expect which is the capital letter and you're missing the special character. So, it will flag it as a problem whereas it will accept this because there is a there is a check that's taking place.

[00:18:19]Now, with all of these checks, you're trying to make sure that the data is validated. And once the data is validated, then you have data integrity.

[00:18:28]So in order for data integrity to take place, you need to have verified data and validated data. Once you get data that is verified and validated, you have data integrity and therefore your data could be trusted to be correct and error-free.

[00:18:48]All right, cool. Right. So I'm putting everything up there for you to see.

[00:18:54]That's the um notes there.

[00:19:17]Any questions? Any specific questions?

[00:19:42]no questions. All right. Nice. That's it there for today, y'all. All right. So, come back next week. Um we will do our next topic and at the end of the topic, I'll teach I'll teach the topic for you all for free cuz Yeah. In the meantime, go and download the Learn It app. Um make it simplett.com/learnit.

[00:20:00]It's in the description of the chat. And if you need a crash course, you could um WhatsApp us or you could click the link in the description because hey, that's what it's there for. But if you can't afford a crash course, we have all the free all the free stuff inside of the app. So go download the app. Make it simplett.com/learnit.

[00:20:19]I'll see youall next week for more IT revision. It's your IT and I am on.

[00:20:29]Okay, so the verse problem is different between functions and formulas. Okay, so I explained that before.

[00:20:34]A function is a set of commands that are predetermined. A formula is a bunch of addition, subtraction, multiplication, and division to be able to get or those of you all in the um backstage. Y'all could um y'all could exit now. Thank you very much. I'll see you next week and you can join the YouTube cuz I just going to be teaching from now on. Right.

[00:21:00]Thanks for playing guys. Next week for sure. There'll be another way to win a free crash course. Normally the winner will get one and then I find some creative way to give the crash course to a second person. In this this case I gave um I gave it to somebody who downloaded the app and left a comment.

[00:21:16]Well, left a comment in the Play Store.

[00:21:18]So next year I might next week I might do it for iOS. I don't know. Yeah.

[00:21:23]But all right, we'll have more. I'm thinking about doing a midweek one.

[00:21:28]Thinking maybe, maybe not.

[00:21:31]Right. Good. So, next on the spreadsheet is the difference between count and count if. So, um yeah.

[00:21:46]All right. Let me go through. So, this is the spreadsheet that I actually do.

[00:21:52]um for this is what I used to teach my classes, right? So those of you all who are in my class, you would know I have one really huge spreadsheet and I explain every single thing in detail on these different exercises. So I give you the exercise, we test it, we see how they do it and whatnot. So let's go through the difference between count and count if.

[00:22:26]All right. So let's start with count.

[00:22:31]Count's job is to count anything that has a number inside of it. So count is going to count only if there is a value.

[00:22:42]A value is a number. A label is words.

[00:22:46]So for example, the number one here, this is a value. The words m o n would symbolize Monday. The word chenise, that is a label. So anytime there's a number in a cell, it's a what? Value. Anytime there are words in a cell, it's a what?

[00:23:05]Label. So count is going to count only values. So that means if I say count from B2 to F2, it's going to count anything that's a number inside here. So if I power one, it will count it. If I power five, it will count it. But if I leave it blank, however, it won't count it. So watch this one that I highlighting here. You see, I highlight the four. Watch how the number four is going to change when I put any number inside by Monday. So I'm going to go inside by Monday and put a five. Did it count? Yes. If I put 90, did it count?

[00:23:35]Yeah.

[00:23:36]And if I put 34, did it count? Yes. But if I delete all of the values, all all it dropped to zero. Right?

[00:23:50]And if I put one, it counts. If I put next one, it counts. If I put next one, it counts. If I put next one, it counts.

[00:24:02]Upon next one, it counts. So count is going to count only numbers.

[00:24:10]Got it?

[00:24:12]Now that's different from count if.

[00:24:15]Count if now is going to do something different. If I say count if, I have to put two things inside the count if. I have to put the range that I want, which is just now I'm going make the space a little smaller.

[00:24:32]So that you could see right here. Right.

[00:24:38]So if I put count if I could say count if B2 to F2, focus on the comma, right? Watch the comma carefully. Count if B2 to F2 has a one in it. So watch.

[00:24:55]I'm going I'm going to zoom in on it so you could see. Right. So this means count if anything inside B2 to F2 has a one inside of it.

[00:25:08]So when I press enter, it's going to say five, right? That's because it looked at the whole of B2 to F2, which is all of this here, and it's like, "Oh, I actually see five ones." Watch carefully.

[00:25:20]Count if B2 to F2 has a one inside of it. Now, if I change the number inside here from one to two, the number is going to drop, but I still have a value inside of it. Before it was counting the value because two was a value. So if I change any of these numbers here to anything other than a one, it won't count it because it was told count only if what is in between B2 to F2 has the number one inside of it. Do you see that?

[00:25:52]So you understand difference between count and count. If count will count anything as a number.

[00:25:59]Count will count anything as a number.

[00:26:00]Count if has specific criteria it has to look for. So now we could take count if to a different level. I could take count if B2 to F2 has the word yes in it.

[00:26:15]This means look at B2 to F2 and look for the words yes. But there's a little trick here. I had to put yes in quotation marks because computers don't like words. In order for you to get it to understand a word, you have to say, "All right, I'm putting this in quotations. Whatever you have between the quotation marks, that's what I want it to look for." So, if I put count if yes, that means it will look for the word yes every single time. So, if I put yes, it it did it once. If I put a yes here, did it twice. If I put yes here three times. If I put yes here, four. If I put no here, it won't go up because it was told only look for the word yes.

[00:26:57]So count if could count numbers, it could count words, it could count anything. But wait, there's more.

[00:27:06]What if I have a bunch of numbers, but they have values inside of them? So let's say I have 1 2 3 4 5 and I want to count if something is greater than two.

[00:27:21]The answer should be three is greater than two, four is greater than two, five is greater than two. So I supposed to get three as the answer. Will it give me three? Yes, it did. How did it know that? Because I said count if anything from B2 to F2 is greater than the actual number two.

[00:27:39]So two is not greater than two. One is not greater than two. But if I change this one to 10, guess what? It's going to count up and it'll be like, "Oh, it's four." Because count if is smart enough to figure out what I want to count because I chose to put the criteria in. Do you understand the difference between count and count?

[00:28:09]If um from the chat somebody asked if we typed A1 inside a cell where you call that you'll call that a a label. Label is anything other than just a number.

[00:28:18]So one um one one one right. So if I type A1 inside a cell A1 that counts as a word. You'll see it automatically aligns left because labels automatically align left and numbers or values automatically align right. So once you have a mixture of numbers and letters, it will be counted as a label, right? Okay, cool.

[00:28:48]All right, so that's the difference between counter and counter. You're welcome. Let's see what else the um let's see what else thing. All right, so we did count and counter.

[00:28:57]Done.

[00:29:02]Advanced filter. All right. So for advanced filter, let me see where the advanced filter is. Is here.

[00:29:21]All right. Advanced filter. Okay. So how advanced filter works is like this, right?

[00:29:27]Let's say I have a set of numbers.

[00:29:31]Um, they look like this.

[00:29:35]But I want to filter out only the things that are from 2010 that are greater than three.

[00:29:43]So I have two parts it.

[00:29:46]I have the table of data which I can clearly show you here. This is the table of data.

[00:29:52]This here is the filter values that I'm going to be trying to filter out. So the table of data going to be here the things that I want to filter out to be here and this is the output here.

[00:30:13]Okay.

[00:30:15]So for advanced filter it looks like this. So you go to data and then you'll see filter sort and filter and then you'll choose advanced.

[00:30:26]Do you see that there?

[00:30:29]Right. When you click advanced it's going to do something like this.

[00:30:35]Going to give you this box here.

[00:30:39]What you want to do is copy to another location. So let me go through the list range is A1 to E7. That is what I've highlighted in yellow. So I've literally said I want to filter out this set of data, right? I want to filter out this set of data by looking at this criteria range which is what I have in green and I want you to put the answer in this location which is A13. So let's take that slowly.

[00:31:11]I want to filter out everything from A1 to E7 and then I want to use the criteria that I put in A10 to A1. So the criteria is anything that's in the column 20110 and greater than three.

[00:31:45]That's what I want to get. And then I want the output to go to A13 to E13.

[00:31:52]So if I was to look at this with my eye alone, which things in column 20110 are greater than three? Is zero greater than three? No. So I'm not supposed to see that. Is um St. Lucia greater than three? No. So I'm not supposed to see that. Is five greater than three? Yes, I supposed to see that. Is seven greater than three? Yes, I'm supposed to see that. Um, Barbados 0 is not greater than three. And Antigga 3 is not greater than three. So, in my filter table, I'm only supposed to see the whole row for Grenada and St. Vincent. If I scroll down, Grenada and St. Vincent has come up because these are the only things that are greater than three. So, what the advanced filter is going to do, it's going to look at this table.

[00:32:31]Then it's going to look at what I asked for, which is anything that's in 201 greater than three.

[00:32:38]Um, show it. And then the output is going to be that. So it's basically a input, a process, and an output.

[00:33:01]Got it.

[00:33:04]Any questions?

[00:33:13]If I do if I don't get any questions, that means you understand. So, I should see the um the scholar emoji.

[00:33:21]All right, cool. Back to the spreadsheet. Why did Serato open? Whoa.

[00:33:27]Now you're going to think I'm secretly a DJ.

[00:33:41]All right. Now V lookup according to the spreadsheet. That's not Hold on. Then close it. Yes, I am sure that I want to close it. 100% sure. All right, let's go. for VLOOKUP.

[00:34:02]All right, VLOOKUP looks like this.

[00:34:07]I have a table here with name, book code, amount, and cost per book. Right, cool. No problem. That making sense? I want to find out the cost per book, but I don't want to have to type it in every single time because let's say I have 5,000 people that come to the library. I don't want to have to type in the cost per book every single time. This table here has the cost of every book. So in a VLOOKUP, there's two tables. There's the main table.

[00:34:33]Main table yellow lookup table green. So the green table is where you look for the price to put in the main table. So I want to put the cost per book inside here.

[00:34:52]In order to do that, I have to do something called a VLOOKUP.

[00:34:56]So watch carefully. VLOOKUP stands for vertical lookup. That's why the V exists. Vertical lookup.

[00:35:14]So that means it's going to look at a table in vertical form. So this is saying look up B2. Where is B2?

[00:35:24]B2 is this value here. So I'm going to look for the letters C3 somewhere. So look up whatever is in B2 one. That is step one. That the first part of the V lookup. The second part of the V lookup is now which table do you want to look at to find the answer? The table that I want to look at is located in G2 to H11 which is this table here.

[00:35:48]So notice what I did. I said, "Look at B2. Look for whatever is inside B2, which is which is the letters C3. Look in this table here and tell me if you see C3." If I go down, down, down, down, down, I realize, hey, look, C3 is here.

[00:36:04]I have found it. But wait, we're not done yet. I found the C3.

[00:36:10]But really and truly what I have to do is I have to get the price that C3 is next to, not the letter C3. So that's why I have the number two. The number two means look in the second column of this table. This this table has two columns. One column is code, next one is price. So I want to look up the code, but I want the second column, which is the 45. So it should give me back 45 as the answer. False means that this table is not sorted in alphabetical order. So just that's basically telling the V lookup. Well, yeah, I don't want to don't don't try to look for it in alphabetical. If you take off the false, it still work like the V lookup will still work if you don't have the false inside of it. But you need to put the false in because it's just basically saying um we didn't sort it. So now the number 45 is here. So let's see if it's correct.

[00:37:07]C3 according to the lookup table matches to the number 45. Is 45 here? Yes. C3 matches to 45 in this table. Is 45 here?

[00:37:16]Yes. B3 matches to eight in this table.

[00:37:20]Is 8 here? Yes. A1 matches to five in this table. Is five here? Yes. D2 matches to 23 in this table is 23 here.

[00:37:30]Yes. All of these are using the same VLOOKUP formula. However, the B2 in this case will change from B2 to B3 to B4 to B5 to B6. So, I could delete this whole thing here and it wouldn't change.

[00:37:48]I'll just click here, click the little notch at the bottom which is called fill handle or autofill and I drag it down and then boom, it'll calculate it every single time because it was told look at this cell, check this table and give me the second column.

[00:38:09]And that's how our V lookup works.

[00:38:21]All right. Um, I am not responsible for the level of diabetes that you're going to have when you get these questions for your exam and it's kick. You and your doctor will have to deal with that.

[00:38:31]Please seek a physician because right now you are like >> let me let me explain something to all you.

[00:38:40]I living with a higher understanding of life.

[00:38:44]All right.

[00:38:46]All right. So, questions. But if it was sorted, would the examiner give it correct true? Yes, the examiner should give it correct for true. If it was sorted, um, put true. If it wasn't sorted, put false. Yeah, that's the only trick that they might have. But, I doubt you'll have too much of a problem because even if it's not sorted, it will still work here. If you put false, as I said, the false is not necessary for it to work cuz I could I could click right here. I can take off this false. Watch. I going to take it off.

[00:39:17]Going to take off the word false and the VLOOKUP will still work because it doesn't need the false to work. However, it's just to show your understanding that okay, I understand that it could be sorted or not sorted.

[00:39:33]So, it's basically approximate match or exact match. Approximate match means it not sorted. See if you could find it.

[00:39:41]Exact match means it's sorted. Yeah.

[00:39:46]Yeah. False could be used if it's sorted or unsorted cuz Excel is smart enough to figure it out. Yeah.

[00:39:52]Yeah. Some passport or passport picture.

[00:39:55]Yeah. That's my expired passport. Yeah.

[00:39:59]I mean really going to make a difference, you know.

[00:40:05]And I really concerned about you all trying to figure out you not like me out here worrying about why the price of things in the grocery so high. That's actually more concerning.

[00:40:27]You know what? XX Moonlight XX-710.

[00:40:32]Go ahead. Find me.

[00:40:42]least of my worries. Oh, graphs and charts. All right.

[00:40:52]Yeah.

[00:40:54]Um, let me see what's in chat. Count A.

[00:40:56]Count A stands for count all. Oh, I didn't I didn't explain count. I was explaining counter.

[00:41:02]Um, count a count. Let me see if I have example. I have example for count a somewhere.

[00:41:09]Yeah. Okay. This is example for count A here. Count A means count all. If there's everything inside a cell, it'll just be there. Yeah.

[00:41:22]Counting will just be like whether your text, whether a number, whether your symbol, I will count you. Doesn't matter. Count A is all inclusive, right? So a chart, charts and graphs.

[00:41:37]Okay. So when you're doing a pie chart, a pie chart is best for two pieces of data.

[00:41:45]So if you have two things, which is an a name and an amount, use a pie chart. If you have six things to do, then you should use a a bar chart or a graph of any chart like that. anytime you have things that go um long. So you have quantity, price, VAT, discount. A pie chart just won't work for this. If I if I highlight this and I try to do a pie chart, it will literally crash out. It'll be like what? How do we even do a pie chart for this?

[00:42:18]It can't.

[00:42:20]All it will just do is um items and Yeah. items and quantity, it will only take the first two columns.

[00:42:30]So, a pie chart is only going to work for two columns. However, if I take this same thing and I use a a bar chart, it will be like, oh, bet we could do that. This is easy. I can I can do all sorts of bar charts to represent this data with all six different things inside of it because that's how um that's how bar chart works. So when you have to use a pie chart, a pie chart is for two columns of data and any other chart is for multiple columns of data.

[00:43:06]Comey, a lot of you got that wrong, but yeah.

[00:43:13]All right. Last thing is rank.

[00:43:17]Rank.

[00:43:19]There are a lot of fumbles with rank.

[00:43:22]Okay. So watch rank. If you understand VLOOKUP, rank is way easier like ridiculously easy. Rank says, "Hey spreadsheet, I want you to rank a particular value which is B2 amongst a set of other values. So rank B2 amongst everything that is from B2 to B16. Why are there dollar signs?"

[00:43:51]because we have to make sure that when we ranking that the dollar signs will lock those sets of values in place. So when I do the fill handle, it's going to realize, oh, I wanted B2 to change to B3, but I didn't want the range to change. If the range changes, I'll have a problem because I won't be ranking correctly. So rank just says check this value against another set of values to see where it stands in terms of stand um ranking or standings. first, second, third, fourth, fifth, sixth, seventh, 8, 9th, whatever. And once you do that correctly at the top and the fill handler going down, it'll rank everything correctly. But you must make sure that you use absolute cell referencing because if you don't use absolute cell referencing, this B2 and this B16, they're going to change.

[00:44:43]So I'll show you what happens when you don't use absolute cell referencing, just for your knowledge. If I don't use absolute cell referencing, it will rank the first one correct, but then when it does the second one, we'll get a problem. You want to know the problem? The problem is B2 changed to B3 and B16 changed to B17. I don't want that to happen.

[00:45:10]I want to make sure that it always stays at B2 to B16.

[00:45:15]So therefore, I'll make sure that I put the dollar signs so that when I do the absolute cell referencing, it didn't change to B3 and B17. It stayed at B2 to B16. And that's the only trick to do with rank and according to the notepad that we have of things that y'all fumbled in the cahoot.

[00:45:54]We done.

[00:45:57]We are done.

[00:46:01]Because right now, because of what you learn, you feel very um was that last person? What was there a question last person? Um what's the difference between currency and accounting?

[00:46:22]Um okay, let me give you example.

[00:46:27]All right. So this is a set of numbers here. Once the dollar sign is right next to it, that is currency. But once the dollar sign is to the left, that is accounting. So this is accounting.

[00:46:39]Accounting dollar sign on the left, numbers to the right. Currency, dollar sign and numbers next to each other.

[00:46:50]Yeah.

[00:46:58]PMT is um multiply the rate by the months by the amount is bas is like simple interest what you call simple interest you remember simple interest principle by rate by time it's just that the Excel people they just call it PMT for some reason I don't know why I can't tell Why?

[00:47:27]But it's literally rate by months by time. But the months have to be in um in Yeah, it had to be in months. It can't be in years. So if if there's something with years, you'll have to convert the years to months.

[00:47:40]But that's all.

[00:47:44]PMT is just a fill in the blanks function.

[00:47:47]Nothing special.

[00:47:55]All right, cool. So, what you have to do is you have to share this with your friends who don't know nothing about spreadsheets and be like, "Hey, there's this guy on YouTube that explained all the hard things for spreadsheets in half an hour." Like, yeah. Um, was that PMT means periodic payment?

[00:48:24]That's the stupidest thing that they could ever name it.

[00:48:28]PMT how PMT means periodic payment. It is not an acronym for PMT like PMT stands for payment like like payment the amount of pay the payment that you have to make. Yeah.

[00:48:51]Like Yeah.

[00:48:57]I don't know. They probably use it for like that. Yeah. I find that a weird name.

[00:49:03]That's a weird name. But all right, I I me.

[00:49:12]So the goal of a database is to fix a major problem is that um uh a database is a place where data is collected, stored and analyzed, right? So, because our database is going to collect data, it's going to store it, it's going to analyze and it's also going to be distributed.

[00:49:59]So there are databases all over the world like we have databases that your phone your contacts on your phone is a database your WhatsApp is a database your Instagram is a database Tik Tok database is a database of a lot of data that's collected stored analyzed and distributed now the reason you have to do all of them is because it it doesn't make sense they collect the data and they just have it stored because there's nothing that you could do with it doesn't make sense you analyze the data and find out things and not distribute it to somebody. So you have to make sure that you let the data do something that's useful, right? Um people that in the chat, you know the drill. When you learn something, you have to send the scholar hat. Do you know the scholar hat? Somebody post the scholar hat for them in the um in the chat. The the graduation hat.

[00:50:43]Um yeah, you should know, right? I need to learn stuff. And remember, I'm teaching so you know, respond, say yes, ask questions, that kind of thing because this is for you. This is exactly what what a lot of students need. So we're dealing with the the diff difficult topics, right? So the first thing definition of a database.

[00:51:06]Good. We're done there.

[00:51:13]Done.

[00:51:16]Right. Data types. Now when you build a database, what you have to do is you have to collect the data in a particular way. So a database is broken down like this. You have the database and the database is like a big block like that. A database is broken down into a bunch of tables.

[00:51:42]A bunch of tables is broken down into a bunch of records.

[00:51:47]And each one of these records is broken down into fields.

[00:51:52]So let's look at it.

[00:51:54]So a database could be like a school.

[00:51:59]Let's say a hospital, right? So you have this hospital.

[00:52:05]The name of the database is called hospital and that's cool.

[00:52:09]The tables that this this database will have will be patients, nurses, doctors, and probably like administration.

[00:52:26]You have ad all the administrators or the author, right?

[00:52:30]Each one of these tables when grouped together form a database because a database is a collection of related tables. Why they say related tables is because clearly the patients table will be related to the doctor's table will also be related to the nurses table will also be related to the admin table. If you add a table to this database and name it like cooks, no um and you name it engineers is clear that engineers is a little bit out of out of place here because um a engineer in a hospital not exactly making sense. So engineer is like out of place. So related tables means that the tables that you have must be related to each other based on the type of database that you're building.

[00:53:27]Right?

[00:53:30]Making sense I need auto follow my right because this will set the foundation. Now from here every database let's say we take the um the patients table the patient's table is going to be broken up into a bunch of records and the record of a patient is going to be something like um let's say the name of the patient is sponge Spongebob.

[00:54:13]Spongebob is 18.

[00:54:16]Actually, Spongebob real old by now.

[00:54:19]Spongebob might be 38.

[00:54:23]And Spongebob came in with the flu.

[00:54:27]And Spongebob is being seen by Dr. X.

[00:54:32]Right.

[00:54:34]So this is the record of Spongebob that is in the patient table that is a part of a bunch of related tables that are part of the database called hospital.

[00:54:46]So a record of a person will be one one particular thing about that person and no one particular set of data of that of that person and a bunch of records make up a table. So if you have a second record of um Clark Kent, Clark Kent, I don't know who I was, probably like 35 and he came in with kryptonite poisoning and he's being seen by Dr. Luther.

[00:55:28]Right? These are two records and these two records make up a what? A table.

[00:55:35]These this table is is put with other bunch of tables that make up the database.

[00:55:46]All right. All you clocking it making sense?

[00:55:55]So tables are a bunch of records. A bunch of records make up the table and a bunch of tables that are related make up the database.

[00:56:08]Right?

[00:56:10]Now, each one of these records has a particular field. So, the name of this field will be first name.

[00:56:22]So the first name field will collect information only about people's first name. Then there'll be another field which will be called surname.

[00:56:38]And the surname field will collect all the information all the data about that.

[00:56:42]And then you have another one called age. Age will only be things that pertain to age. Right? Each one of those fields when you join them together creates a record. So if you collect information about somebody in a bunch of fields, you end up creating a record. So now you could clearly see how a bunch of fields when you put together creates a record. When you create a bunch of records, you create a table. When you have a bunch of tables, you create a database. And that's the um that's the concept of databases so far.

[00:57:19]So a database is a place where data is collected, stored, analyzed and distributed. And this is the structure of how the database is going to going to be laid out. A bunch of fields, individual pieces of data strung together. When you string together all the individual pieces of data, you create a record. After you create a record, you put a bunch of records together, you create a table. After you create a a bunch of tables together that are related, you create a database.

[00:57:47]Everybody with media is over.

[00:57:51]Anybody getting the um the aha moment and LIKE all right.

[00:58:02]So now let's take now let's take the um let's see what we reach so far.

[00:58:10]difference between tables and fields. We just we just dealt with that.

[00:58:21]All right. So now we have to go on to data types.

[00:58:26]So let's go through data types.

[00:58:32]Now data types follow a particular uh particular rule. So let's say you have These are the fields that we're dealing with. We collecting data from somebody and we want to collect their first name.

[00:58:47]We want to collect their surname.

[00:58:50]We have to collect their age. We want to collect their date of birth.

[00:58:58]And we want to see if they are they have insurance or not.

[00:59:08]Right? So there are different data types that you could use for each one of these.

[00:59:14]First name follows a data type called text.

[00:59:19]Text is anything that's on your keyboard. So text could be a b question mark slash asterisk full stop and the and a number like one one two yeah text could be anything like that.

[00:59:35]So anything that is that is going to be text you're going to put there. This is why phone number like 1-868 555 there's a question that you all got wrong 777 well not you all got wrong but a lot of people got wrong. This is considered to be text. The reason it's considered to be text is because these guys right here, the dashes have turned it into text.

[00:59:59]If it were just if it were going to be number, well, we'll get to just now.

[01:00:03]I'll tell you giving a number. Surname will also be text because surname could be anything. Age will be number because age will only be the digits 0 to 9. So somebody put in their age they can't put um 19 that will not be accepted because what is expected is that the actual number 19. Right?

[01:00:41]The other data type that you can have is date slash time.

[01:00:51]Date slash time means that you'll be able to put in a data birth and it will follow a particular format like 0604 26. Your exam is on the 14th 14th.05.26.

[01:01:04]This is day slash time because it's going to basically break this down into month, no day, month, year.

[01:01:14]That's what trying to do. Day, day, month, month, year, year. So, date slash time. And then there's another data type that's called boolean or yes slash no.

[01:01:30]This is if something is either true or false. is often represented by a checkbox. So if you have a tick, that's a yes. If you don't have a tick, that's a no. So this will be yes. This will be no.

[01:01:46]Following me there? Those are your major data types. There is another one called long text, but they really do the long text anymore. But yeah, so those are the major data types that you have to think about when you do those data types. when they ask a question about which data type will be used, it will be used right. Um person asks about integer, integer um may be mentioned on newer versions of like Microsoft access but I think all the older ones they will only have number. If they do have integer that means you're thinking about code, you're thinking about algorithms, you're thinking about problem solving but it's not really um problem solving, right?

[01:02:25]The only other data type that they could have which somebody just mentioned in the chat is currency. So let's think about money owed.

[01:02:37]You have money owed the data type that you're going to put there is called currency.

[01:02:43]That means anything that you put in. So if you put in the number like if you put in the number 200 it's going to translate that to dollar sign 200.00 0 0 with decimal places that will be um currency right?

[01:03:01]If you are if you are thinking about things like um real and float and integer and all of that drama. Yeah, that's next week. Next week that's algorithms, pseudo code and program code.

[01:03:27]That's a different that's a different set of data types. Right? So next week when we do algorithms and programming, I'll explain I'll explain that to you all. But as it pertains to databases, these are the data types that they will kind of push for you. the things that in red. Okay, so text, number, date and time, boolean, and currency. Those are the major data types. We're good there.

[01:04:00]Data types done.

[01:04:02]Okay.

[01:04:05]So now let's say you build a whole database like you have a whole bunch of data tables upon tables upon tables and all of the tables have rows of information and you have tables of this. So we have the hospital we have the nurses we have the doctors we have all these tables and they all just they're all there and we have this big thing called a database.

[01:04:32]It doesn't make sense. You have all of this data and you can't get anything out of it. So, in order to get stuff out of here, you have to run a query.

[01:04:42]A query is asking a question about the database. So, query asking, a question about the database.

[01:05:03]So the query is going to ask a question of our database and when you ask a question database you're basically going to ask questions like let's say for example we have age and people have a particular age. So you check to see age that's going to do a query and put it on a different color. Let's say you want to do a query and you be like okay find all the people who have age greater than um 17. This query is a query to find all the adults or you want to find a you want to do a query that says um um medical status no insurance status equals no. That means find all the people from the database that don't have insurance. So you want this will find people who don't have insurance.

[01:06:10]The reason you ask queries of the database is because the the database is full of information. This this table here could have like this database here could have 10k people inside of it. and you don't want to read um you don't want to read through 10k records. All you want to do is go through the the um the database and find the people that matter. So after you do this query, you might be able to find all the people that are over 17 might actually be 50 people. All the people that have no insurance might actually be 10 people. But the query is going to ask a question about the database. And the question at your answer is going to give you a table that has just this information.

[01:06:56]So you get a smaller table that is more manageable so that you'll be able to handle what you want. So that's the point of a query.

[01:07:05]Everybody understand why a query is necessary for a database, right?

[01:07:15]So a query just asks questions.

[01:07:26]All right. So, let's go with calculated queries now.

[01:07:31]So, a calculated query is when you do a query on a database, but it doesn't have anything inside the database created for it already. So, you have to create the query for yourself. So let's say for example you have a database with um item price and quantity.

[01:07:53]These are the the fields in the table.

[01:08:00]So they have bread and the bread is $20 and the quantity is two. But somebody asked for a report with the the cost of all of the bread.

[01:08:15]But there is no field called cost or total cost. You could create a field called total cost when you do the query by putting total colon price asteric quantity.

[01:08:35]This now will create a field called total that will add on to the table here and then it will calculate the total for you by multiplying whatever is inside price which is 20 by two and then show you the answer which is going to be $40.

[01:08:55]So the calculated query is going to create a field for you. That is why it's called a calculated query.

[01:09:06]Calculated queries are for you to add something to the database that wasn't there before, originally didn't exist.

[01:09:12]But you were able to make the calculation for yourself by first creating a name for the query saying which two fields to use and what operation to do to calculate it.

[01:09:23]But this is the format that your calculator query must take which is the name of the field a colon and then the two things in brackets right yes um yeah you have to put this under criteria in the section in the database here no this not going under criteria going by field name in the field name section.

[01:09:57]I will show you a database just now where it goes. Right?

[01:10:01]I'm going just go through this theory stuff and then I'll show you all a real database and you can see what it will look like.

[01:10:07]Right? So, calculated queries done.

[01:10:15]All right. So, let's talk about relationships now.

[01:10:19]No, you have to use square brackets, not the um not the not the normal brackets.

[01:10:28]Um relationships, right? So, let's go relationships now. So, let's say you have um patient ID as one field and then you have like first name and then surname right this is one table here so you have patient ID 001 and surname is Sponge no first name is Sponge is Bob and then patient 002 the first name is um Clark Kent right then you have a and this table is all patients.

[01:11:20]Then you have another table called doctors.

[01:11:25]Doctor's table has a doctor ID, the ID and then our first name and a surname.

[01:11:38]This doctor ID is 00 one. No, Dr. ID could be 101.

[01:11:47]Dr. is 101. Dr. um strange person.

[01:11:57]In this table, you also have what patient they handling.

[01:12:02]So, Dr. Strange handles patient 002.

[01:12:06]So, what a relationship does is it's going to relate these two tables based on a particular field. So which two fields do we have in common between these two tables? Patient ID is one table and patient ID here is another table. So this means that in order for you to figure out which patient a doctor is checking or which doctor a patient has, you would be like, "Okay, patient 002, let me trace it along this line here. Watch how tracing it. I've taken patient 002. I tracing it along this line. Trace trace trace trace trace trace trace. Go go go.

[01:12:50]And when I reach here, I realize patient 002 is here. Who is the doctor that handles patient 002? Strange person.

[01:12:59]That is how a relationship takes place.

[01:13:01]Our relationship takes place because on one table there is a primary key PK primary key and then in the other table there's a foreign key FK. The foreign key is the is the field in the other table that relates to the primary key.

[01:13:15]So there's always go from primary key to foreign key. That means this patient 002 patient 002 could get get checked in this table to see that their doctor is strange person.

[01:13:33]Now if I add another doctor to this table or if I add another patient to this table, you'll see this. Let's say I add a third patient and the patient is also 0 0. The patient ID is 003 and name is John and Phil.

[01:14:10]Right, John Bill, whatever the case is. Right, we have a next doctor in this table here.

[01:14:20]This doctor name is Dr. 102 and the person the doctor is like um Dr. Doom.

[01:14:33]Dr. Doom is checking patient 001. So if I want to figure out who is taking care of patient 001, I check what's their patient ID. I go across to this table and I go down and I'll be like, "Oh, 001 is being checked by Dr. Doom."

[01:14:51]So you'll know that your doctor is Dr. Doom because your patient ID matches to this table here. And that's how it is.

[01:14:58]So that's how relationship works.

[01:15:00]primary key. One table that's unique goes to a foreign key which will have another table.

[01:15:10]You all following?

[01:15:13]Primary key is always from one table and the foreign key is a field in the other table that has the same data.

[01:15:30]So if we were to do a query and we'd be like okay who is patient 001 being seen by the answer to the question will be Dr. Doom.

[01:15:56]How do we know that? because I was able to trace patient 001 is the primary key here. Go to this next table with foreign key where I find 001.

[01:16:06]I know that Dr. Doom is that patient. So then you ask the Dr. Doom. Yeah.

[01:16:13]Why is the doctor ID and patient in the same? Oh yeah, this was actually supposed to be doctor 1002.

[01:16:20]But it could be the same because they're two different tables. the person that asks the question about the doctor ID and the patient ID mean the same. It's possible because once they're in two different tables, the data won't clash.

[01:16:32]You can't you can't have the same patient ID in the same table. So a doctor could be doctor 01 and a patient could be patient 01 because they're two two separate tables.

[01:16:43]But generally you try to give the naming convention for each table to have a different type of ID number.

[01:16:52]Okay. that answers your question.

[01:17:01]All right. So that's primary and foreign keys and one to many relationships and onetoone relationships. All right. So let me explain what one to a onetoone relationship is.

[01:17:13]If I have a relationship between um a let's say I have a teacher to students.

[01:17:25]This is a one teacher to many students because one teacher has many students.

[01:17:36]So how that would relate to the table is one teacher will have many students basically. Let's say you have one mother to child. You'll have one mother to one child.

[01:17:51]That's a onetoone relationship.

[01:17:56]Then you could have a um a many to many relationship. You could have um many um what's the example for many to many? Many to many is hard. Okay. Many to many, right? Many cars use many roads. Can use many roads. So that means you could use any car could go on any road if you're building a relationship between cars and roads. Yeah.

[01:18:33]That's um that's a many to many relationship. So cars to rose many many one to so you just have to think about how the relationships make sense and just say it out in a sentence.

[01:18:46]One to many one teacher has many students. One mother has many has one child um could have one child. Many cars could use many roads and that will that will get you there.

[01:19:02]That's one to many relationships.

[01:19:06]Um what's the only thing that I miss out? I missed out grouping. Grouping in reports. Okay. So if I have a table with um let's say the data is ID, department, ID, name and department.

[01:19:32]So this person's ID is one, their name is Bob, they work in sales.

[01:19:39]Ideas two, John works in sales.

[01:19:43]ID is three is Bill. Bill works in accounting.

[01:19:50]And ID4 is Tim. Tim works in engineering.

[01:19:56]When you're trying to create a group, you have to find a field that is um which is which has repeats. So is the are there repeats in here?

[01:20:10]Nope. Are there repeats in here?

[01:20:13]Nope. Because the names could be different. Are there repeats in here?

[01:20:17]Yes, there are. So, if I do a report, I could pull out all of the people that work in sales. So, I could say, okay, the people that work in sales are Bob and Jan because I group the reports by that. So, let's say I had 10,000 people.

[01:20:35]I could create a report that groups all the people in sales and groups all the people in accounting and groups all the people in engineering. So I could send specific information to people in sales, people in engineering, people in accounting. And that's the whole point of grouping. Grouping is for when you have to do a report. Reports must be grouped by something that makes sense.

[01:20:54]If you don't have the ability to group things, that means you have no fields that are repeating.

[01:21:02]All right, everybody following me there?

[01:21:09]So grouping reports.

[01:21:19]So that's essentially what um what those are the things that um this is a good representation of the things that generally give students troubles in in databases.

[01:21:29]And you're welcome. I zooming out a little bit just in case you all want to take a screenshot or whatever the case is because if I were to list out the things that students struggle with every time when they do a database questions these would definitely make the top five. Top five for sure.

[01:21:47]But they'll always keep in mind a database is a collection a place where data is collected, analyzed, stored and distributed. And in order to do that you have to break down this database into tables, records and fields. When you create the fields, you must be able to put the correct data types for the fields. When you put the the data types for the fields, then you could start to um do queries.

[01:22:15]After you do the queries, you'll be able to look for certain things.

[01:22:20]Um in order to do more complex queries, you need to be able to link the two databases by make um building a primary key and a foreign key. And once you link the databases, you have to know how to do the relationships. And once you have a table with database with information, you'll be able to group them, right? But calculated queries are inside here somewhere. It's not exactly me teaching through the whole of databases, but I realize that you all know a lot about databases already from the cahoot, but I just needed to to put things um to put things in in perspective. Right. So, I'm scrolling back out so y'all could see it. It's um this the best I could do.

[01:22:57]Let me see if I can get the whole thing.

[01:22:59]Yeah, that look like the whole thing there. You I had to get the left side of the screen cuz this is more white. This is my whiteboard that I teach other things.

[01:23:08]The exact same things that I taught um last week. Look them right here.

[01:23:12]Remember when we went through data integrity? For those of you that were here from the first the first live data integrity, then the things that we did in spreadsheets, I explained all of that.

[01:23:24]And then now we explaining databases.

[01:23:27]Next week will be algorithms and programming.

[01:23:31]And this is your quick crash course.

[01:23:36]So those of you all who want to learn about algorithms and programming, next week we'll do the cahoot. After the cahoot you will learn. Those of you all who want past paper videos, um, download the learn it app. Go to learn it. Make it simplept.com/arnit.

[01:23:52]The link is in the description. You could follow on Tik Tok. You could follow on Instagram. You'll see all the videos that we have here. The um the the information that you need because obviously you all want to study.

[01:24:16]So yeah, download the app and you will see all the information.

[01:24:21]You see all all all of the information, right? The person I'll give the crash course to tonight if you if you want the um if you want the crash course the app person that ask about the app is um let me show you.

[01:24:48]All right. Right. So, if you go to make it simplett.com/arnit, I'll put it in the in the chat.

[01:25:09]Yeah. Click that link and you will get this app. And the app literally has subjects listed out.

[01:25:20]And for those of you all who do in it, I have every single past paper video worked out. PDF notes inside um videos for all playlist for all different things. Past paper answers, the same pass paper answers that you want to see. We have the past paper answers in video form and PDF form. And yeah, but we added a whole set of anxiety.

[01:25:52]Okay. So, what topics we dealing with here? Pseudo code terms. All right. Pseudo code terms. All right. So, when you're writing, um, let's start off by this.

[01:26:02]You are a human being and as a human being, you are trying to talk to a computer.

[01:26:12]A human being trying to talk to a computer has problems because on this side human being is using words English.

[01:26:22]On this side the computer is using ones and zeros binary.

[01:26:30]How do we get from our English to binary?

[01:26:38]So in order to get to the get to the binary we have to create something in the middle ground here called pseudo code.

[01:26:48]Pseudo means type of.

[01:26:54]So this is a type of code.

[01:27:02]type of code means that you are going to write your going to write your instructions in such a way that it's closely resembles code what a computer actually understands. So in the middle here you might have pseudo code up here you have flowcharts.

[01:27:24]So a human being could do pseudo code flowcharts. Somewhere here you have narrative.

[01:27:34]So the three ways of representing algorithms are narrative flowcharts and pseudo code.

[01:27:44]Closer to the end here you have something called um assembly language.

[01:27:58]Assembly language is closer to what a computer understands because it uses words like add, sub, mull. So addition is add, subtraction is sub, mull is multiply and then the actual ones and zeros this is called um machine code.

[01:28:22]So what our computer actually understands is machine code.

[01:28:30]Sorry I was a highlight there. It actually understands machine code. What we actually understand is English.

[01:28:36]Everything that we do in between is to get to machine code. So our job, our goal is to move from English and get to hear machine code. In order to do that, we start off by writing our algorithms in narrative. After we write it in narrative, we could draw it in a flowchart. After we draw it in a flowchart, we could write it in pseudo code. After we write it in pseudo code, it gets converted to assembly language and then it gets converted to machine code. So that's the process of talking to a computer. So whenever you're thinking about algorithms, this is how it starts. This is how it works. That's the whole reason you have to write pseudo code, right? Chat, all you good with my there so far? Everybody um everybody following the concept because you know feedback is necessary in this world to ensure that learning is taking place. You all know you have to send the scholar hats if you're learning something um if you're not learning anything well tough.

[01:29:30]I'm not seeing any scholar hats in the um in the chat but that's okay. Um these seasoned veterans will know. All right. So when we now deciding to talk to a computer, we start off by most of the times writing pseudo code.

[01:29:50]Pseudo code is broken broken down into three parts. There's our input, there is a process, and then there's a output.

[01:30:10]all all um all pseudo code basically follow that, right?

[01:30:14]So for inputs, you could use certain words like get, read, and you could use back inputs.

[01:30:25]For process, you could use a equal sign, you could use a arrow that's pointing backwards, or you could say set.

[01:30:36]And for output you could use print output or display.

[01:30:47]These are called pseudo code terms because we speaking a language. We're trying to speak the language of the computer. And in order to speak the language of the computer, you have to start to start to say words in a particular way. It's like our languages.

[01:31:11]In English, if you want to say certain things, you'll use a exclamation mark, you use a comma, you use a full stop.

[01:31:16]English is like a code. So pseudo code is like a code for the language of a computer.

[01:31:23]Got me so far?

[01:31:31]So that's where we get pseudo code terms from. Okay, pseudo code terms check.

[01:31:41]Right now when we're writing these algorithms or when we're writing these these instructions for a computer, we have to break them down into what a computer understands. So a computer if even if we write all the words that we want a computer understands data data has particular types.

[01:32:06]So you understand the English language because the English language tells you A to Z are valid letters and 0 to 9 are valid numbers and that is English to you.

[01:32:22]But remember a computer does not like English. A computer likes numbers. So if we have to take the data types and we have to give the computer numbers, there are three ways that a computer represents things, right? So the first way that it represents it is called um integer.

[01:32:43]A integer is whole numbers positive or negative. Right? This is the symbol for positive also negative. So example of an integer is example 50 minus 50 27 - 27 those are all integers.

[01:33:10]So a computer loves numbers. We know that for sure because remember our computer deal with ones and zeros all the time. So the ones and zeros are the closest thing to numbers. That's why we we use binary.

[01:33:22]So in the end numbers make it easier for computer not English. So integer is one way that a computer understands number.

[01:33:29]That's one data type. The next data type is um real slash float but it's really floating point.

[01:33:48]It's a very very very long story to explain why they use the word float and why they use the word real. But long story short, this is how computers actually see numbers as like very strange representations of real numbers that tend to close to be close to zero. But there's a lot of math behind it. Anyhow, real or float um decimals positive or negative.

[01:34:23]Right?

[01:34:25]So example 261.325 that is a valid real number 1802.11 that negative 102.11 that's a valid real number it must have a decimal so if you if you if a computer declares something as a a real or a float and is a whole number even if it's a 100 it'll put 100.0000 however how much zeros you'll put because it just basically forced to deal with things as a decimal. So that's a real or float. Ideally all of these things come back down to binary but I'll explain that here just now. Right. The last thing is it's um character.

[01:35:11]So a computer sees things as characters.

[01:35:14]So a character is anything on your keyboard. So it could be an exclamation mark, it could be a question mark, it could be a asterisk, it could be a a, it could be a w, it could be a comma.

[01:35:23]doesn't matter what it is. Each one of these things is represented by a number and the number that's represented by it is actually a binary value. So we see an exclamation mark but what a what a um what our computer sees is one one.

[01:35:45]That is what a exclamation mark is to a computer. The letter A, I can't remember what it is in ASKI, but it's like one 0 one one zero one one one I don't know something like that. This is what the computer actually sees. So technically speaking, a computer just sees ones and zeros, but they are represented in three possible ways for the computer.

[01:36:07]Integers, real or float, and then character.

[01:36:14]Any questions here? We good?

[01:36:30]That's not what I wanted.

[01:36:34]That's what I wanted.

[01:36:42]Cool.

[01:36:45]I don't see this color. Do you know? Hi guys. Send this color.

[01:36:52]This makes me this makes me realize that you'll learn something. That That's what I wanted to send. Yeah, that um that helps. I don't get to see the reactions because my head I'll be looking down sometimes. Okay.

[01:37:05]So now let's go into the program compilation process before I do the loops and those sort of things. Right.

[01:37:12]So technically what happens when a when we send a when we um actually no I will do the loops first it'll make more sense. Yeah loops. So when we talk to a computer there are three um things that you use to talk to the computer when you give instructions.

[01:37:28]You could give instructions sequentially you could give it selection or you could give it loop.

[01:37:40]Sequential means step by step.

[01:37:45]Step by step that's what I wanted to say by step. So example of sequential will look something like this.

[01:37:56]Start get a get b. c is equal to a + b.

[01:38:05]Print c. Stop.

[01:38:11]Everything is sequential here because you can clearly see that this step leads to that step and that step leads to that step and that step leads to that step and that step and that step. So it's sequential step by step.

[01:38:23]Selection however is um choice based on a condition.

[01:38:35]So sequential would look like this.

[01:38:38]It'll be um start get age. If age is greater than 17 then print um adult.

[01:38:58]Else print child.

[01:39:05]End of.

[01:39:07]Stop.

[01:39:09]So here's how selection works. Selection is going to get a variable. So it's going to start get a variable called age. Based on what age is, it's going to make a decision. So the same age here is the same age here is the same. Yeah.

[01:39:22]Same age. So whatever age they put in, they're going to check to see if it is greater than 17. You have two options.

[01:39:29]You have the yes, it is greater than 17, do this. Or you have the no, it is not greater than 17, do that. So the jump that takes place from here could either go here or here.

[01:39:39]Which one? It depends on the answer to this part here. So this here has an answer.

[01:39:46]And the answer could be yes or no. So based on this condition, if the answer is yes, do this one. If the answer is no, do that one. That is what selection is. Selection is basically choosing between two possible options. Right? You with me so far?

[01:40:14]A loop now is repeat steps until a condition is met.

[01:40:31]So that now takes us to the part where you all kind of struggled with in the cahoot which is loops. There are two types of loops. There are definite loops and then there are indefinite loops.

[01:40:49]So let's go to a definite loop. A definite loop is something where you know where the start is and where the finish is. So, run two laps.

[01:41:02]How much times you going to loop around the um the track? Two times. Cuz you definitely know run two laps. Indefinite loops is run until you are tired.

[01:41:19]How much time is you going to make it around? Some people will make it two laps. Some people make it one lap. Some people will make it.5 laps because they're so unfit, but it's indefinite because you don't know when it's going to stop.

[01:41:33]So definite loops, you know when it's going to stop. Indefinite loops, you don't know when it's going to stop. So a definite loop is usually signified by a for loop. So four C is equal to 1 2 10 do. How many times is this loop going to run?

[01:41:54]is going to run 10 times. What are we going to do 10 times? I don't know.

[01:41:58]Print hello.

[01:42:04]So, what going to happen is the word print the word hello is going to be printed over and over and over and over and over and over and over and over and over and four.

[01:42:20]So this loop is going to print the word hello every single time for 10 times because they're going to count from 1 to 10. That means it's definite.

[01:42:34]But if I say while that's I'll put it in green so you could see.

[01:42:42]If I say read num and then I say while num is not equal to zero do print hello and while what's going to happen is how how many times is Hello going to print out.

[01:43:17]That's a question.

[01:43:28]How many times is hello going to print out?

[01:43:31]We don't know. Do you know how many times hello is going to print out? No.

[01:43:35]Because it depends on what number this person puts in here. So if the person puts in a five, is five not equal to zero? Okay, print hello. The person puts in a four, is four not equal to zero?

[01:43:46]Print hello. If the person puts in a three, yeah, person puts in 26, yeah, keep printing, keep printing. But as soon as the person puts in a zero, it' be like, hold on, zero and zero are the same. The condition here is not true anymore. So because it's not true, then we will stop the whole while loop because it depends on this thing here.

[01:44:08]making it continue. That's what makes it indefinite because you don't know when it's going to stop because it depends on some number that you have no control over. But with a definite loop, you have full control over it because you could say how many times you want it to run.

[01:44:23]That's the difference between a definite loop and an indefinite loop.

[01:44:27]So definite loops definite loop will be or indefinite is while and repeat.

[01:44:47]for a while do and repeat until these are the two indefinite or is the definite?

[01:45:03]We good there?

[01:45:13]I'll take that as a yes. all just soaking it in and like whoa.

[01:45:20]Nobody ever taught me this in my whole life.

[01:45:25]But you're here and you're here, right? So that that deals with definite and indefinite loops.

[01:45:42]uh very reach now right now let's go to levels of programming languages so as I said before all a computer understands is ones and zeros all we understand will be English so there is high level And then there is lowlevel highle languages will be things that humans live in. So humans love up here.

[01:46:22]So this is the human realm and there are generations. There's fifth generation, fourth generation, third generation.

[01:46:39]So fifth gen is like talking. So it's like English words.

[01:46:50]Fourth generation is like shortened English words.

[01:46:59]And third generation is like pseudo code but kind of like code/ pseudo code.

[01:47:07]Right. So you're starting to get closer to what the program to the what the computer understands because remember up here is English and down here is ones and zeros.

[01:47:25]So when we reach lower down now we end up reaching to second generation and first generation. Second generation is assembly language and first generation is binary or you might see machine code.

[01:47:52]Machine code means this is actually what the computer wants but this is what we can give. So we live in this area here but the computer lives in this area here. So fifth generation languages they are very high level. So this might be like um narrative words um port generation will be like um broken English code will be like the only thing I could put is code I'll give you example just now assembly language is like um something called pneumonics and binary is ones and zeros.

[01:48:53]So here are some examples of levels of these language. Narrative words. Well, narrative words is basically the English language.

[01:49:03]English will be broken out into SQL.

[01:49:07]SQL will be like get update something like that. So the name of the language is SQL. Code is where you live which is Pascal C Java JavaScript all in different things that is code. Pneumonics is like add sub multiply jump.

[01:49:36]They are like how you text. So you like how all your text like SRS ly. No. How are seriously?

[01:49:46]This is my ank status showing here. No.

[01:49:48]Okay. You wouldn't say for real. You put FR for real. But that actually means for real.

[01:49:56]So when you say it like this, you are like fifth generation. But when you say FR, you are like second generation if you were talking to a computer.

[01:50:06]So if you say Sirius and then you say SRS, it's the same thing. Sirius is fifth generation. SRS is second generation.

[01:50:16]If you were to break it down further, you could take your Sirius and turn it to ones and zeros and the computer will be like, "Oh, you're talking to me."

[01:50:24]Because really and truly, a computer only understands ones and zeros. So, the generation of languages works like that. High level languages versus low-level languages. It goes from fifth generation, fourth generation, third, second, and first. But low level is second and first. And the high level is third, fourth and fifth.

[01:50:46]making sense.

[01:51:10]All right. And then the program compilation process, it goes something like this.

[01:51:17]This is real easy to understand. When you type up all of your code and you put your for loops and your Y loops and all them kind of thing and you have the start and then the stop and you type up all that code. This is called this is called um your source code.

[01:51:41]Your source code has to get to ones and zeros.

[01:51:48]The ones and zeros is called object code.

[01:51:55]In order to get there, they need they could use either one or two people. They could use an interpreter or they could use a compiler.

[01:52:05]An interpreter is going through going to go through this line by line. So the interpreter will be like good good not good good good. The compiler goes through the total.

[01:52:20]So the compiler will be like yes or no. So the compiler will go through all of the lines and at the end it will say if it's passed or it doesn't pass because a compiler a compiler really have time to go through line by line. A compiler is like the that English teacher that will read your whole essay and then leave all the comments after if it doesn't pass. But an interpreter will check it line by line and try to run each line one at a time.

[01:52:48]Once they translate it, it will change to object code. And once it reaches to the object code stage, you'll be like, "Yay, we should object code." But how does your computer actually run the program?

[01:53:00]These ones and zeros now have to go through some process called linking.

[01:53:06]and the link in changes it to aexe file. I don't know if you ever saw.exe file, but you all probably saw it when you downloaded a virus. Aexe is a executable file.

[01:53:20]Um, and this is what actually runs the program.

[01:53:29]So somebody will sit down, write out all of the code that's called the source code. Then they will use a compiler to compile it or interpreter. And then when the compiler and the interpreter says yes, it is okay, it turns to object code. When it turns to object code, it has to go through linking. Linking now is going to find all of the things that you need for this program to run. And then it'll actually be a program that runs. And that's the whole um compilation process.

[01:54:03]And did I save your life? I don't know. Not too sure if I did.

[01:54:16]And with that, we have crashed the course of your programming life. These are more the top of things that you all genuinely didn't understand from the cahoot, but that's okay. So, I'm going to zoom out now so y'all could kind of see it, but there's a lot there's a lot to see. So, I'll just Okay, I'll zoom in on this part here at the top and you could like screenshot it and then I'll zoom in on the other one afterward.

[01:54:50]All right. So because of the level of interaction aliyah_e aliyah, you'll get a free crash course.

[01:55:18]All right. So, screenshot that there and um email it um send me send a picture of it to one of the social media links and one of the social media people will um will deal with it for you. Okay. So, just screenshot that. I type that there.

[01:55:32]Aliyah gets a free crash course and send it on um send it on Instagram or Tik Tok or or yes Instagram might be easier but wherever you send it we'll get WhatsApp to the office whatever the case is find me and you get the free crash course and right so I scrolling down now so y'all can screenshot this Hot.

[01:56:03]Yeah. Now go down.

[01:56:19]Right. So, um you could al come back to the video and screenshot it. Right.

[01:56:23]Okay. Now again I'm I'm letting you know that there is a app called Learn It.

[01:56:29]Download the Learn It app. The description is in the um in the it is in the description of the video.

[01:56:35]I'll paste it at the end. But there is a full playlist on algorithms on the YouTube channel. Full full full. The the link to the playlist is in the description of this video. If you go through this playlist, I'm telling you it covers everything from algorithm. So if you think I just like explain stuff there, these videos here explain algorithms in the greatest detail. It's literally what I would teach in the crash course. This is the exact notes that I use in um in in teaching. So it will teach you everything, flowcharts, trace tables, all of that. The link is in the description. Watch that whole playlist from start to finish. You could put it on 2x if you want and watch through it and you will understand algorithms. There's very few people that um that watch this and didn't understand algorithms. Let me just show you. Hold a number for like look at some of the comments for this one. Right.

[01:57:33]You have taught me more than my own teacher. This teacher is not only great at teachers, he has human. I love that.

[01:57:38]I love your videos. Wished I found you sooner. This is very helpful. Thank you, sir. I'm glad I came across your channel. Nice and comprehensive video, sir. Thanks. Learning is fun for real.

[01:57:47]La pseudo code. Good job. Good video.

[01:57:49]Excellent. What software do you do to use here? Background music is annoying unnecessary. All right. You're welcome.

[01:57:54]Thanks for coming. What? What did I respond?

[01:58:00]Yeah. Right. Hey, you know you had to get the troll comments, right? Yeah.

[01:58:05]Yeah.

[01:58:07]Yeah. Right. Good. So, that is um that's basically it for algorithms. If you download the app, the learn it app, there is a million things there for you to learn. Even for those of you all who have maths on Tuesday, we have real maths videos and a free crash course on maths inside the Learn It app. So, go and download it. You will see. I'm not I'm not um I'm not playing with you. I'm letting you know that there's a lot of resources out there. And what we've done is we've created an app that basically puts all of the resources that a C6 student needs, all the videos that Yeah.

[01:58:44]all the videos that you need inside there. So go to the link in the description. I'm going to paste all of the links now to make sure that you see that I'm not lying to you. So right before the live ends, I'm going to paste it and then you all could click the links and go to them. But I