You will need to install Python, Jupyter, and Pandas for this course.

This video will walk you through installing Pandas and Jupyter on your machine. You can also reference this post I have created https://www.metasnake.com/blog/pydata-dev.html

We will be leveraging the Jupyter environment through this course. This will introduce you to it.

Here are the files for this course. You will need to download them to follow along and master SQL selection.

In this section I will demo the content for the course. If you want to follow along make sure you have the notebook and have installed Jupyter. You will see an example of what we will go over in the course.

Here I demo connecting to a Sqlite database using Python. Most languages have an API for interacting with a database. The language will usually have a "driver" for a given vendor. This class is vendor and language agnostic (we use Python but just because it ships with Sqlite so it is easy to use). You will want to consult the documentation for your language and DB to determine best practices for your combination.

Let's start with the basics. Pulling out all the columns or a subset of them. Oh yeah, also we might want to limit the number of rows returned, so let's do that too.

As you learn SQL you will run into exceptions. Sometimes, you will get an error. Sometimes, you might have logic errors (or just bad SQL) that runs but returns the wrong (or an empty) result.

Counting is probably the most basic operation of a data scientist. It is probably one of the most useful metrics as well. Counts are used all over the place. Let's see how to do them with SQL!

You need more than selection. You don't want to look at a million rows of data. You want to look at data that is relevant. Since we are lazy, let's use a computer (or SQL) to help us with that.

We will also need to know how to filter by date. Let's jump in!

Might as well look at filtering with strings as well!

Missing data. The bane of our existence. It is tricky and confusing. Let's try and clear away some of the confusion.

Counting is one way to aggregate rows to a single value. There are other aggregate functions that we can use to summarize data. And we can summarize by arbitrary columns.

Let's put a bow on it. Make it look pretty. Here's some lipstick. Oh, and sort it too! Can you sort it by this column as well?

SQL allows us to filter before an aggregation and after one!

A best practice is to be away of a potential security hole called SQL Injection. Let's explore that and how to prevent it.