Original subtitles

‫What is a table and what is a table in the relational model?

‫Well, we've looked at multiple, multiple examples of how to break down data.

‫And each and every time we've broken down data, we've broken them down into these entities or objects

‫or concepts, whatever you want to call them, be it a user, a student, a teacher, and a table is

‫a representation of that object.

‫So here we have the object user and we have a table.

‫And when we create a table, we give it a name.

‫That name is of that object.

‫So we're going to call it user.

‫So a table has a name that's the first and foremost important thing we need to know.

‫Each table has a name and that name relates to the concept of the data we're going to store.

‫Think of an Excel sheet and giving the Excel sheet a name.

‫And then when we look at a table, we can see that we have these things at the top called columns.

‫And each column represents a specific type of data.

‫We have ID here, which is an incrementing number.

‫It goes up one, two, three, four or five.

‫Then we have first name that contains the name of the user, the first name and last name.

‫And then we have their gender, male, female and so forth, and then we have their date of birth.

‫Which follows a specific year, month, day, so what we can see here is that a table has a name and

‫a table has columns that store specific types of data, kind of like an Excel sheet, but an Excel sheet.

‫The names of the columns are already named.

‫If you've seen Excel, you can see A, B, C, D here we get to choose the names.

‫So that's very important because we're specifying what type of data we want to store in each column.

‫And then here next to the columns, we have these rows also like an Excel sheet, these rows of data

‫and each and every row is a singular piece of data.

‫It represents one single piece of data for that table.

‫So here you can see McGeeney, me, the instructor, and you can see my date of birth, my sex and my

‫ID as a user.

‫That is one piece of data and that data is split up into columns that represent each and every piece.

‫Very, very important.

‫So here we can see the relationship between what a table is and what an Excel sheet is, like I said,

‫you can see over here every sheet has a name, kind of like a table, has a name, and every sheet has

‫columns, A, B, C, D, E, F.

‫Kind of like our table has columns, but our columns are more specific.

‫We are actually saying what we want to store in each and every column where in Excel the columns are

‫generic, they're pre named, so to speak, so that it doesn't matter what data you put in here, it's

‫going to accept any type of data.

‫You just know that your column name is A, B or C.

‫You can go a bit farther and excel and give specific columns at row one, you could put first name here,

‫last name here, date of birth here, just so you know what's going to be in these columns.

‫But you you would lose a row.

‫But that being said, the relationship between the two is very close, except in the relational model,

‫a table has much more nuance.

‫What do I mean by nuance?

‫There's a lot more details here.

‫We're very, very, very specific in what we want to store and how we want to store it.

‫So now that we know that, let's take a closer look at what a column is and how that gets defined.