Use COUNT(DISTINCT) to find unique customers
Quick one — how many unique customers do we actually have in the database? I keep hearing different numbers from different teams and I want one source of truth before the board meeting.
Each hint you reveal reduces the XP you can earn. Try the query first.
Use `COUNT(DISTINCT customer_id)` on `dim_customers` instead of `COUNT(*)` — DISTINCT ensures each ID is counted once
You can alias it: `SELECT COUNT(DISTINCT customer_id) AS total_customers FROM dim_customers`
The result should be a single row with one number. If you're getting multiple rows, remove any GROUP BY