task TRIM / LOWER / SUBSTR / REPLACE · easy

Emails used more than once

Some shoppers share an email once you ignore letter case and surrounding spaces. Return clean_email and shopper_count for every such email used by more than one shopper.

what to return

Columns

clean_emailshopper_count in this order

Rows

2 rows · any order

Watch for

clean_email = the email trimmed and lowercased.

Ignore shoppers with no email.

Skill

Normalise text before comparing it. Refresher: Filter groups with HAVING →

expected result

Your query should return exactly these columns and values. Run it and compare.

data you can query

Sample rows from each table. Each column shows its type underneath; → marks a link to another table.