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Free SQL course

SQL for Data Analysis and AI

Module 10

Query Validation: Reconciliation, Edge Cases, and Sanity Checks

About 75-95 minutes of guided work.

By the end of this module you can reconcile a figure against an independent source, catch an order-of-magnitude error in ten seconds, test the edge cases that break real reports, and explain a variance instead of rounding it away.

Units

  1. Unit 10.00: Row-count reconciliation as a habit
  2. Unit 10.01: Magnitude checks that catch order-of-magnitude errors
  3. Unit 10.02: Edge cases: empty groups, refunds, and boundaries
  4. Unit 10.03: Explaining a variance instead of rounding it away
  5. Unit 10.04: Re-validating after the final small edit

Module work