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In this video we'll take a look at what we're going to cover in this course.
[MUSIC]
0:00
Hello and welcome to your next
exciting step in your SQL journey.
0:04
I'm Andrew a database user, lifelong
learner and teacher here at Treehouse.
0:09
In this course we're going to
build on that foundation of
0:14
knowledge you've already acquired.
0:17
You should be familiar with performing
simple select statements and
0:19
filtering using WHERE clauses.
0:23
If you don't understand what any of that
means you should check out the course
0:25
prerequisites, I've listed them
in the teachers notes below.
0:29
SQL databases can store massive amounts of
data, getting the information you want and
0:32
presenting it in a human readable and
digestible way is a necessary skill for
0:39
anyone needing information
from a database.
0:44
Let's think of a couple of ways that you'd
want to retrieve data in a database.
0:48
Imagine you wanted to present
products to a user of an online store
0:55
alphabetically by name.
0:58
You'd do this by retrieving that
information from the database,
1:00
in a specific order.
1:04
Or you might want to display
all products by price
1:05
from the least to the most expensive,
for example.
1:09
Again, you'd request the data
in a specific order.
1:12
If you run a news site,
1:16
you may have thousands of news
stories going back tens of years.
1:17
Your readers don't want
all of those stories, so
1:21
you'll only request the latest
articles from the database.
1:24
Limiting what you
retrieve is very helpful,
1:27
especially when your database
holds lots and lots of data.
1:30
Data can be inconsistent,
especially when end users are involved, so
1:34
being able to manipulate strings of text
and make it consistent is super important.
1:39
Maybe you want to make all emails
lowercase and last names uppercase.
1:45
Instead of just looking at
individual rows in a table
1:50
you may want to group them together and
ask questions about them.
1:53
For example, you may want to count all
products bought on a certain day or
1:57
maybe you want to get the total
amount of revenue generated by sales.
2:02
You can even get the maximum or
minimum review ratings for a product.
2:06
Grouping data like this
is called aggregation.
2:11
Then there's reporting tools for dates.
2:15
SQL code provides tools for
creating dates and searching by dates.
2:17
These come in handy when you're
looking at ranges of dates.
2:22
For example, say you wanted a report
showing all sales in the last seven days.
2:25
Using SQL, you simply retrieve all
records from seven days ago to today.
2:31
This kind of dynamic
reporting is very useful.
2:36
This same SQL query can be run everyday
to return just the latest results.
2:39
In this course we're going to take
a look at all the different coding tools
2:46
that the programming language
of SQL has to offer.
2:50
By the end of this course you'll be able
to generate database results suitable for
2:53
reports, or even a dynamic website.
2:58
Whether you're an analyst, scientist,
marketeer, support staff, or
3:01
developer, this course is for you.
3:04
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