Introduction to Databases and SQL

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TRANSCRIPT

Hello everybody, and in this video, I want to give you an overview of what databases are and a little bit about the database, that we'll be using and then towards the end, we'll have a little experiment, that shows you, should hopefully enforce the point as to why using databases is useful, as opposed to storing data in some other kind of medium, like a text or Excel. So first of all is what is a database? Well, a database is a very efficient way to store highly structured data for querying and in data management. So what I mean by querying is really just question answering, so I have a ton of data and I wanna ask a question about it, what's a good way to do that and so that's a very high level definition, that I gave there, maybe a more concrete thing to do would be to equate databases to spreadsheets, so I have an example of an Excel workbook set up here and so you can conceptually think of the data stored inside of a database as being kind of like in a workbook like this, so it is a workbook, we have these different, down here at the bottom, you can see, we have different sheets here, so I have one sheet that says Track, I can go to another sheet, that says Album, let me make that a bit larger, we can see that, so I have another Track that has all of the albums here and then I can go back to Track, so these are two different sheets and in database lingo, these would be considered two different tables and again, they're even organized kind of conceptually in the fact that they look kind of like a table, here, let me make this a bit bigger.

So you know, we have a header row here, that tells me what each of the entries looks like, just like you would expect in a regular table and I have a bunch of these rows, which are entries in this table, same for Track here, I have a top, I have some information here, that gives me just basic information about what each of these columns means and then I have, let me expand that out, so you can see, and then I have rows, which are entries in this table and so this database lingo also uses the same conceptualization of rows and column, so a row would be a slice this way and rows are just entries inside of these tables and then columns represent things, represent slices across all of the rows, so here's a Composer column inside of this column, has all of the different composers for each of the particular pieces of information, so you can kind of conceptually think of a database as being organized in a spreadsheet fashion like this. Now they have lots of advantages over just using spreadsheets that I'll get to in a second, but conceptually you can think of a database as being organize ... https://www.youtube.com/watch?v=33KMgEz26_s