From the course: SQL Essential Training

Relational database theory - SQL Tutorial

From the course: SQL Essential Training

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Relational database theory

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- Okay! To start, let's get familiar with some basic vocabulary. When we're talking about relational databases, there are a few key terms you just need to know. First up, data. What is it exactly? Well, if we're being proper, data is the plural of the word datum, and a datum is defined as a piece of information. So data are pieces of information like your last social media post, whether that's text, images, or video, or the last phrase you search for on Google. Second, a database. It's simply a collection of data. That data can be organized in many different ways, but it's usually organized in tables. Now, what are tables? Well, that's the third key term you need to know. You know, in Trinidad, where I'm from, the word lime used as a term to mean you're hanging out. You're going to chill out with some friends. You're going to lime. When used like this, lime has absolutely nothing to do with the fruit. Similarly, in SQL, a table has nothing to do with the type you eat your food on. In the world of SQL, tables are made up of rows and columns. Rows run left to right and columns up and down, think Excel spreadsheet. Each row represents a single piece of data called a record. And yes, (upbeat music) I'm thinking of some great reggae records right now, but it's not that type of record we're talking about. Each column represents a specific attribute of that data, such as name or address. In order to get the data, take a look at it, and analyze it, we use a special language called SQL, short for Structured Query Language. By the way, SQL and SQL are terms used interchangeably that mean exactly the same thing. SQL includes many different commands or keywords. One of the most common is SELECT. The SELECT statement allows us to specify the columns we want to get from a table and include in our results. By understanding these basic concepts, you're on your way to mastering relational databases. So let's lime with some SQL.

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