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Roadmap · stage 2/13

Python + SQL

Stage 2 of 13 · 19 resources · 2 categories

What this stage is

Python + SQL is stage 2 of 13 in the DE//AGENT roadmap. It currently holds 19 resources: 10 tutorials, 4 references, 2 skills across 2 categories.

What it teaches

The two languages everything else is expressed in.

What you can do after this stage

  • Write a set-based SQL query with window functions
  • Write typed, packaged, tested Python

Exit gate

Gate: You can move a dataset from an API into a table with tested code. The stage deliverable: project-dbt-warehouse-tests.

Gates are self-assessed — the roadmap does not track your progress; it tells you what to be able to do before moving on.

Categories in this stage

Python (1), SQL (18)

Registry resources for this stage

Sorted by composite score — provenance, completeness and trust, per the scoring model:

ResourceTypeDifficultyVerificationScore
DuckDB / MotherDuck MCP ServerMCP serverbeginnercommunity44.4
SQL ReviewSkillbeginnercommunity39.9
SQLFluff Core Rule PackRule Packbeginnercommunity39.7
SQL Query Plan ExplainerSkillintermediatecommunity38.5
SQL ReviewerAgentbeginnercommunity34.5
First hands-on — a correct SELECT with a justified joinTutorialbeginnercommunity34.15
Fix SQL lint with the SQLFluff core rule packTutorialbeginnercommunity34.15
Review SQL for fan-out joinsTutorialbeginnercommunity34.15
Run the full SQL review pass on a PRTutorialbeginnercommunity34.15
The relational mental model — sets, grain, and NULLTutorialbeginnercommunity34.15
Capstone — the SQL correctness checklistTutorialintermediatecommunity34.15
Incident — the numbers doubled and no alarm firedTutorialintermediatecommunity34.15
Production gotchas — NULL traps, implicit casts, silent driftTutorialintermediatecommunity34.15
Read an EXPLAIN plan and pick the one fixTutorialintermediatecommunity34.15
Window functions — keep the grain, rank the rowsTutorialintermediatecommunity34.15
DuckDB DocumentationReference—community27.7
Python Official DocumentationReference—community27.7
SQLBolt — Learn SQL with Simple Interactive ExercisesReference—community27.7
Jev and DuckDB: Plain-English Conditions in SQLReference—community23.55

Documented learning objectives

  • Prove a join cannot fan out before writing it
  • Spot NULL-unsafe `NOT IN` and `=` predicates
  • State the grain of a result set in one sentence
  • Configure SQLFluff for your warehouse dialect
  • Customize rules for team standards
  • Integrate SQLFluff into CI/CD pipelines
  • Fix legacy SQL debt incrementally
  • Read a plan bottom-up and name the expensive node

Continue the progression

← Foundations · Data Processing →

← Full roadmap · All learning topics