Builds Power Query (M language) transformations for Excel data models, covering query folding and its performance implications, common reshaping steps like unpivot/merge/append/custom columns, and connecting to refreshable external sources such as CSV, SQL databases, and web APIs. TRIGGER when: the user asks to import, clean, reshape, or combine data with Power Query or Get & Transform; the user mentions M language, applied steps, query folding, or the Advanced Editor; a query is slow to refresh or pulls an entire external table instead of filtering server-side; the user needs a refreshable connection to CSV/SQL/web data. DO NOT TRIGGER when: the task is only about writin…
