SQL QuestSQL Interview Questions › Aggregation & Grouping

Day-of-Week Order Pattern (strftime)

MediumFreeQuerying BasicsAggregation & GroupingDate Functions

Operations wants to know which days of the week see the most orders — useful for staffing fulfillment shifts.

Use strftime('%w', order_date) to extract the day-of-week ('0' = Sunday, '6' = Saturday). Show dow (the digit) and order_count. Group by dow. Order by dow.

This is the simplest day-of-week bucketing — no JOINs to a calendar table, just the strftime trick. If you need human-readable day names, you'd add a CASE on top.

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Schema

orders

order_idcustomer_idproductcategoryquantitypricetotalorder_datecountrystatus
11Laptop ProElectronics11299.991299.992024-01-15USAcompleted
22Wireless MouseElectronics249.9999.982024-01-16Canadacompleted
33Office ChairFurniture1349.99349.992024-01-17USAcompleted

Expected output: 1 → 2, 3 → 1, 6 → 1

Hint

The hint for this one spells out most of the query, so it stays in the editor. Reach for SELECT, GROUP BY, Date Functions, and open the hint there if you stall.

Concepts

SELECT GROUP BY Date Functions strftime

Practise the topic: SQL practice questions · GROUP BY exercises · Date function practice

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