Evaluation Order and Common Problems
Window functions and GROUP BY
Summary and Review
18. Summary

Instruction

Excellent. It's time to wrap things up. Let's review what we learned in this section:

  • Window functions can only appear in the SELECT and ORDER BY clauses.
  • If you must use window functions in other parts of the query, use a subquery.
  • If the query uses aggregates or GROUP BY, remember that the window function can only see the grouped rows, not the original rows.

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Exercise

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