Cellwise · SQL track

Building reports

Shares, complete lists and top customers.

Report queries combine everything: joins, grouping, conditions and calculations. Work out what one row of the result should be, then build towards it.

One useful trick: a condition in a LEFT JOIN’s ON clause filters what gets matched without dropping rows from the first table.

What you’ll do

• Share of the total
• Every city, even with no sales
• Find the best customer