Baseline — Day 1
Using a safe practice dataset, write down how you would find one order and its status history without SQL. Evidence: the fields, filters, and expected rows you think are needed. This exposes gaps without letting AI solve the investigation.
Stage 1 — Read and filter one table
Outcome: Write SELECT, FROM, WHERE, ORDER BY, and LIMIT queries. Resource: A short syntax guide plus the approved schema documentation. Practice: Retrieve one order, then filter a status table by order ID. Evidence: Saved queries and result screenshots. Check: Missing LIMIT, wrong column, or incorrectly quoted values.
Stage 2 — Combine related data
Outcome: Explain keys and use one JOIN to connect an order with status records. Resource: A visual explanation of primary and foreign keys and one reviewed example. Practice: Join the relevant documented tables and sort events chronologically. Evidence: Query, results, and a sentence explaining why each row appears. Check: Duplicate rows or an incorrect join key.
Stage 3 — Investigate defensively
Outcome: Handle NULL values and verify that a query answers the ticket question. Resource: Examples of NULL checks and simple aggregates. Practice: Investigate two anonymized cases and note what the data cannot establish. Evidence: A brief investigation log and one query for Friday review. Check: Treating missing data as proof or changing data in a read-only task.
Final task
Independently investigate a suitable support ticket: define the question, choose documented tables, write and test the query, verify suspicious results, and summarize findings plus limitations. AI may explain syntax or critique the finished query, but you choose the evidence and conclusion.