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Hello and welcome to your next exciting step in your SQL journey.

I'm Andrew a database user, lifelong learner and teacher here at Treehouse.

In this course we're going to build on that foundation of

knowledge you've already acquired.

You should be familiar with performing simple select statements and

filtering using WHERE clauses.

If you don't understand what any of that means you should check out the course

prerequisites, I've listed them in the teachers notes below.

SQL databases can store massive amounts of data, getting the information you want and

presenting it in a human readable and digestible way is a necessary skill for

anyone needing information from a database.

Let's think of a couple of ways that you'd want to retrieve data in a database.

Imagine you wanted to present products to a user of an online store

alphabetically by name.

You'd do this by retrieving that information from the database,

in a specific order.

Or you might want to display all products by price

from the least to the most expensive, for example.

Again, you'd request the data in a specific order.

If you run a news site,

you may have thousands of news stories going back tens of years.

Your readers don't want all of those stories, so

you'll only request the latest articles from the database.

Limiting what you retrieve is very helpful,

especially when your database holds lots and lots of data.

Data can be inconsistent, especially when end users are involved, so

being able to manipulate strings of text and make it consistent is super important.

Maybe you want to make all emails lowercase and last names uppercase.

Instead of just looking at individual rows in a table

you may want to group them together and ask questions about them.

For example, you may want to count all products bought on a certain day or

maybe you want to get the total amount of revenue generated by sales.

You can even get the maximum or minimum review ratings for a product.

Grouping data like this is called aggregation.

Then there's reporting tools for dates.

SQL code provides tools for creating dates and searching by dates.

These come in handy when you're looking at ranges of dates.

For example, say you wanted a report showing all sales in the last seven days.

Using SQL, you simply retrieve all records from seven days ago to today.

This kind of dynamic reporting is very useful.

This same SQL query can be run everyday to return just the latest results.

In this course we're going to take a look at all the different coding tools

that the programming language of SQL has to offer.

By the end of this course you'll be able to generate database results suitable for

reports, or even a dynamic website.

Whether you're an analyst, scientist, marketeer, support staff, or

developer, this course is for you.