Objective and professional context
The fictional export has A version 1 at 10000 cents, A version 2 at 12000, and B version 1 at 8000. Summing all three records counts an obsolete value. A current-order model instead selects the highest declared version for each key; the completed source contract must say what happens when a version is tied or missing. The free sample has no ties, but a real pipeline must detect rather than silently resolve them.
Your practical assignment
Write the current-order table, sum it, then change A version 2 to 13000 in a copy. Explain which result should move and why the source must be preserved.
Worked solution and interpretation
Current A is 12000 and B is 8000, giving 20000 cents. The changed copy gives 21000. The raw export sum is not the current-order total. Keep both source versions and record the selection rule.
Verification, mistakes and limits
Repeated keys can represent corrections, child rows or actual duplication. Declare grain before deduplicating. dbt models can express a dependency, but they still need source-key/domain tests and independent reconciliation. Do not claim the free Python control executed a dbt adapter.
Continue with evidence
Keep the unchanged data, your implementation and a changed-input result with a short note explaining what you can and cannot conclude. These free companions do not change saved course progress. The published course catalogue shows deeper assignments available under your current permissions. Keep your conclusions proportional to the evidence you have inspected.
Authoritative reference
Official technical method reference; it does not validate fictional outcomes or your own software environment.
Try the activity before reading its reference. Keep your sources, commands and assumptions with your work. Companion activities are unsaved self-practice and do not award a certificate or change lesson progress.