SQL pattern · P11 · 20 problems

Dates and timestamps

Graded problems on dates and timestamps, from easy to hard.

20 problems · about 3 h 30 min in all
Start with problem 01Paid Orders in a Date Window · 5 min
Learn it first · P11The month that loses its final afternoonBETWEEN on a timestamp column stops at the start of the last day and drops the rest.Read the lesson →

Easy

7 problems · about 43 min
01Paid Orders in a Date Window5 min →02Daily Order Counts5 min →03Customer Tenure in Days5 min →04Weekday Name for Each Login5 min →05Extract the Year and Month Number5 min →06Orders per New York Business Day8 min →07Show Login Times in Each User's Time Zone10 min →

Medium

8 problems · about 1 h 20 min
08Weekday and Weekend Paid Revenue7 min →09Paid Revenue per ISO Week6 min →10Daily Orders, Including Days with No Orders8 min →11Events per 15-Minute Interval6 min →12Days Between Consecutive Logins8 min →13Hourly Events on a 23-Hour Day15 min →14Order Totals on a 25-Hour Day12 min →15Convert Daily Local Schedules to UTC Run Times15 min →

Hard

5 problems · about 1 h 30 min
16Customer Activity for Every Day in a Date Range12 min →17Revenue by Fiscal Year and Quarter12 min →18Business-Hours Revenue Across Time Zones25 min →19Recover UTC Times from a Repeated Local Hour25 min →20Support Performance Scorecard with Different Denominators20 min →
Up next · P12

The lookup that misses a value that looks identical

9 practice problems. An equality check fails on a stored value with hidden spaces or different capitalization.

Practise P12Read P12