Unit 1 · Data sources and extraction¶
Before you can chart anything, you need the data — and it never arrives on your desk ready to use. It sits in a database behind a password, in a file somebody exported, or behind a web address that answers in JSON. This unit is the "farm and loot" stage of the game: you learn where data lives, connect Apache Superset to it, and write the SQL that brings home exactly the rows you need.
| Learning outcome | Hours | Term |
|---|---|---|
| RA1 — Extracts data from different data storage platforms. | 10 | 1st |
What you will learn
- Explain the data lifecycle and why a table of numbers is not enough on its own
- Tell apart the kinds of data source (database, CSV, Excel, JSON, API, open data) and what each needs to let you in
- Connect Superset to a database and load a CSV into it
- Write SQL that filters, sorts, groups and joins tables in SQL Lab
- Save a result as a dataset or as a table in the destination database
- Get the same data into Power BI and compare the two approaches
Lessons¶
| # | Lesson | What it covers |
|---|---|---|
| 1 | Data do not speak alone | Anscombe's quartet and the four stages of the data lifecycle |
| 2 | Data sources | Databases, CSV, Excel, JSON, APIs and open data |
| 3 | Connecting Superset to a database | Host, port, user, driver — and your first CSV upload |
| 4 | SQL Lab: filters | SELECT, WHERE, ORDER BY and LIMIT |
| 5 | SQL Lab: groups | Aggregates, GROUP BY and HAVING |
| 6 | SQL Lab: joins | Two tables, one key: INNER JOIN and LEFT JOIN |
| 7 | Datasets and destination | Physical and virtual datasets, storing results, APIs as a source |
| 8 | Getting data with Power BI | Connectors and import in the commercial tool |
What you are graded on¶
The three assessment criteria of the unit's learning outcome, and the lessons that train each one.
| Criterion | Official wording, in English | Lessons |
|---|---|---|
| a) | Connects to the data sources, configuring the access system and their nature. | Data sources · Connecting Superset · Getting data with Power BI |
| b) | Sets up filters and queries to extract the data, taking its characteristics into account. | SQL Lab: filters, groups, joins |
| c) | The data is processed and stored, integrating it into its destination. | Datasets and destination |
The datasets for every lesson are on the Resources page.