QuerydrillOrders per customer
An SQL exercise from Querydrill. Solve it with a SQL editor in your browser, checked on the rows it returns and again on changed data, and it is checked the moment you submit.
The task
Return every customer name with the number of orders they placed, including customers with 0 orders.
What this exercise teaches
Keeping zero rows is a frequent interview trap: LEFT JOIN and count the right-hand key.
A hint if you get stuck
LEFT JOIN and COUNT a column from the orders side.
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