Function table / Level of detail / Largest customer revenue

Largest customer revenue, from Tableau to SQL

Aggregates customer totals once within each region. Below, 8 sample rows go through the calculation and through the SQL, and both return the same numbers.

Calculated field

MAX({ INCLUDE [Customer] : SUM([Revenue]) })

Sample data

RegionTeamCustomerRevenueSeatsDate
NorthCedarAster12042026-01-05
NorthCedarAster8022026-02-05
NorthCedarBirch30062026-01-12
NorthPineClover9032026-02-14
SouthElmDahlia20052026-01-08
SouthElmDahlia10022026-02-08
SouthAshFern7532026-01-20
SouthAshFern2512026-02-20

The same calculation as SQL

WITH customers AS (SELECT Region, Customer, SUM(Revenue) total FROM input GROUP BY Region, Customer) SELECT Region, MAX(total) FROM customers GROUP BY Region ORDER BY Region

Runs the example above.

Result

Regionresult
North300
South300

Same rows from the calculation and from the SQL in DuckDB.

Where a naive translation goes wrong

  • MAX of invoices misses customer totals spread over several invoices.

    Naive SQL

    SELECT "Region", MAX(Revenue) AS result FROM input  GROUP BY "Region" ORDER BY "Region"
    Regionresult
    North300
    South200

    Matches the calculation

    WITH customers AS (SELECT Region, Customer, SUM(Revenue) total FROM input GROUP BY Region, Customer) SELECT Region, MAX(total) FROM customers GROUP BY Region ORDER BY Region
    Regionresult
    North300
    South300

Signature

MAX({ INCLUDE [Customer] : SUM([Revenue]) })