Join tables without multiplying the story

The curriculum

1. Ask a question the data can answer — Free preview

   Define a decision, an observation and a useful denominator before writing code.

2. Make invalid records visible — Free preview

   Parse a small dataset into validated records without hiding rejected observations.

3. Turn an analysis into a reusable function — Sign-in access

   Separate a calculation from input/output and check its boundaries.

4. Join tables without multiplying the story — Sign-in access

   Use keys, grouped queries and reconciliation checks to make SQL results trustworthy.

5. Describe variation before choosing a headline — Free preview

   Distinguish typical values, unusual observations and uncertainty about the future.

6. Design a chart that survives questions — Sign-in access

   Choose clear units, honest scales and a comparison that answers the decision.

7. Build a pipeline that fails informatively — Sign-in access

   Connect validation, aggregation and a deterministic output with explicit failure behavior.

8. Deliver the Community Meter decision pack — Sign-in access

   Combine code, checks and a careful recommendation in a complete local project.