Exploring Astronaut Activities in SQL
Welcome to your webinar workspace! You can follow along as we analyze the data in a SQL database and visualize the results.
To set up your integration, create a PostgreSQL integration with the following credentials:
- Integration Name: Astronaut Codealong
- Hostname: workspacedemodb.datacamp.com
- Database: astronauts
- Username: astronauts
- Password: astronauts
Exploring our data
Let's start by looking at the table we will be working with.
Let's inspect the purpose column in greater detail.
What are the most common types of EVAs?
Let's start to get a rough idea of the most popular types of EVAs astronauts take by using CASE expressions.
We are now ready to build this into a final query!
How much material has been extracted from EVAs?
Skimming through the purpose column, we also saw numerous references to extracting rock/dust or geological material. In this case, it will be difficult to extract the total quantity across the columns. Regular expressions to the rescue!
We will define a pattern to extract the total pounds extracted per EVA, and then sum them up. Let's first do a sense check of the data.
Okay, we now know that the format of the pounds extracted is always number lbs of rock/geologic. We can construct a pattern to detect this and extract the number!
To do so, we will make use of:
\d+to match one or more digits.\.?to match zero or more periods.\*to match zero or more digits following the optional decimal place.()to specify we only want the digits.\sto match the whitespace (i.e., spaces).[]and|to specify we either want to match "geologic" or "rock".
Let's put this into action, using SUBSTRING() to extract our pattern!
Now we can use a CTE to calculate the total amount!