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Customer Purchase Gap Analysis

advanced~12 min40 pts
📊 View Insights

Problem

The retention team wants to understand purchase frequency patterns. Calculate the average, minimum, and maximum gap (in days) between consecutive purchases for each customer.

Schema: Customer

ColumnType
CustomerIdINTEGER (Primary Key)
FirstNameTEXT
LastNameTEXT
CompanyTEXT
AddressTEXT
CityTEXT
StateTEXT
CountryTEXT
PostalCodeTEXT
PhoneTEXT
FaxTEXT
EmailTEXT
SupportRepIdINTEGER (Foreign Key → Employee.EmployeeId)

Schema: Invoice

ColumnType
InvoiceIdINTEGER (Primary Key)
CustomerIdINTEGER (Foreign Key → Customer.CustomerId)
InvoiceDateTIMESTAMP
BillingAddressTEXT
BillingCityTEXT
BillingStateTEXT
BillingCountryTEXT
BillingPostalCodeTEXT
TotalNUMERIC(10,2)

Requirements:

  • Use LAG() to get each customer's previous invoice date
  • Calculate day gaps using EXTRACT(EPOCH FROM (a - b)) / 86400
  • Aggregate per customer: AvgDaysBetween, MinGap, MaxGap, PurchaseCount
  • Order by AvgDaysBetween ascending (most frequent buyers first), limit to 15
CTEWindow FunctionsLAGDate FunctionsaggregationUberSwiggy
📊
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Topfolio

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company

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