Function table / Table calculations / Percent of regional total

Percent of regional total, from Tableau to SQL

Divides each period revenue by its regional total. Below, 8 sample rows go through the calculation and through the SQL, and both return the same numbers.

Calculated field

SUM([Revenue]) / TOTAL(SUM([Revenue]))

Compute using: addressing Period; partitioning Region

Sample data

RegionPeriodRevenueCost
Harbor112070
Harbor2180100
Harbor3180120
Harbor4240140
Upland19050
Upland2150110
Upland3null90
Upland4330190

The same calculation as SQL

SELECT CAST(("Revenue" / nullif(sum("Revenue") OVER (PARTITION BY "Region" ORDER BY "Period" ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING),0)) AS DOUBLE) AS result FROM input ORDER BY "Region", "Period"

Runs the example above.

Result

RegionPeriodRevenueCostresult
Harbor1120700.166667
Harbor21801000.25
Harbor31801200.25
Harbor42401400.333333
Upland190500.157895
Upland21501100.263158
Upland3null90null
Upland43301900.578947

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

Where a naive translation goes wrong

  • An unpartitioned SQL window mixes independent regional calculation sequences.

    Naive SQL

    SELECT CAST(("Revenue" / nullif(sum("Revenue") OVER ( ORDER BY "Period" ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING),0)) AS DOUBLE) AS result FROM input ORDER BY "Region", "Period"
    RegionPeriodRevenueCostresult
    Harbor1120700.0930233
    Harbor21801000.139535
    Harbor31801200.139535
    Harbor42401400.186047
    Upland190500.0697674
    Upland21501100.116279
    Upland3null90null
    Upland43301900.255814

    Matches the calculation

    SELECT CAST(("Revenue" / nullif(sum("Revenue") OVER (PARTITION BY "Region" ORDER BY "Period" ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING),0)) AS DOUBLE) AS result FROM input ORDER BY "Region", "Period"
    RegionPeriodRevenueCostresult
    Harbor1120700.166667
    Harbor21801000.25
    Harbor31801200.25
    Harbor42401400.333333
    Upland190500.157895
    Upland21501100.263158
    Upland3null90null
    Upland43301900.578947

Signature

SUM([Revenue]) / TOTAL(SUM([Revenue]))