Use QUERY to reshape data

I need the sales table reshaped into a compact view grouped by customer and product so the director can see monthly totals on one sheet. Create a query that pulls OrderDate, CustomerName, Product, Quantity, and Total, filters out cancelled orders, and outputs a table with Month, CustomerName, Product, Sum of Quantity, and Sum of Total sorted by Month then CustomerName. Put this on the 'Monthly Sales' sheet and leave the source untouched.

Before I send this to finance, make the reshaped table easy to audit. Put the filtering condition and date range at the top so a reviewer sees what was excluded, make the sums obvious, and surface any customers with duplicate name spellings or null product codes. Recommend improvements to the QUERY so a budget reviewer can trust the aggregates at a glance.

I used QUERY to group orders into Month, CustomerName, Product and sum Total, but March's totals are lower than expected. The buyer, Elena in procurement, will question missing revenue. I can share the query text and the source table but I don't know if the problem is an incorrect range, wrong date parsing, or excluded statuses. Diagnose the most likely issue and the safest change to the query to restore March totals without pulling cancelled orders.

We repeatedly lose trust in the monthly aggregates after imports or when multiple people update the source sheet. Identify the pattern that causes these shifts and recommend one change in workflow plus one change in the query structure that will stabilize the reshaped reports and make them auditable by finance.