Calculated field
DATEPART('weekday',[shipped],'sunday')
Sample data
| shipment | shipped | received | text | year | month | day | hour | minute | second | lat | lon | wkt |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2024-12-29 | 2024-12-29T16:25:40 | 2024-12-29 | 2025 | 2 | 25 | 9 | 25 | 40 | 10 | 106 | POINT (106 10) |
| 2 | 2024-12-30 | 2024-12-30T16:25:40 | 2024-12-30 | 2025 | 2 | 26 | 10 | 25 | 40 | 10.1 | 106.1 | POINT (106.1 10.1) |
| 3 | 2025-01-01 | 2025-01-01T16:25:40 | 2025-01-01 | 2025 | 2 | 27 | 11 | 25 | 40 | 10.2 | 106.2 | POINT (106.2 10.2) |
| 4 | 2025-01-31 | 2025-01-31T16:25:40 | 2025-01-31 | 2025 | 2 | 28 | 12 | 25 | 40 | 10.3 | 106.3 | POINT (106.3 10.3) |
| 5 | 2025-02-28 | 2025-02-28T16:25:40 | 2025-02-28 | 2025 | 2 | 29 | 13 | 25 | 40 | 10.4 | 106.4 | POINT (106.4 10.4) |
| 6 | 2025-03-15 | 2025-03-15T16:25:40 | 2025-03-15 | 2025 | 2 | 30 | 14 | 25 | 40 | 10.5 | 106.5 | POINT (106.5 10.5) |
| 7 | null | null | null | 2025 | 2 | 31 | 15 | 25 | 40 | 10.6 | 106.6 | POINT (106.6 10.6) |
| 8 | 2024-02-29 | 2024-02-29T16:25:40 | 2024-02-29 | 2025 | 2 | 32 | 16 | 25 | 40 | 10.7 | 106.7 | POINT (106.7 10.7) |
The same calculation as SQL
SELECT CAST(date_part('dow',shipped)+1 AS BIGINT) AS result FROM input ORDER BY shipmentRuns the example above.
SELECT DAYOFWEEKISO(shipped)%7+1 AS result FROM input ORDER BY shipment
Written for this dialect; not run here.
SELECT EXTRACT(DAYOFWEEK FROM shipped) AS result FROM input ORDER BY shipment
Written for this dialect; not run here.
Result
| shipment | shipped | received | text | result |
|---|---|---|---|---|
| 1 | 2024-12-29 | 2024-12-29T16:25:40 | 2024-12-29 | 1 |
| 2 | 2024-12-30 | 2024-12-30T16:25:40 | 2024-12-30 | 2 |
| 3 | 2025-01-01 | 2025-01-01T16:25:40 | 2025-01-01 | 4 |
| 4 | 2025-01-31 | 2025-01-31T16:25:40 | 2025-01-31 | 6 |
| 5 | 2025-02-28 | 2025-02-28T16:25:40 | 2025-02-28 | 6 |
| 6 | 2025-03-15 | 2025-03-15T16:25:40 | 2025-03-15 | 7 |
| 7 | null | null | null | null |
| 8 | 2024-02-29 | 2024-02-29T16:25:40 | 2024-02-29 | 5 |
Same rows from the calculation and from the SQL in DuckDB.
Where a naive translation goes wrong
- Sunday-based weekday numbering differs from ISO Monday-based numbering.
Naive SQL
SELECT isodow(shipped) AS result FROM input ORDER BY shipment
shipment shipped received text result 1 2024-12-29 2024-12-29T16:25:40 2024-12-29 7 2 2024-12-30 2024-12-30T16:25:40 2024-12-30 1 3 2025-01-01 2025-01-01T16:25:40 2025-01-01 3 4 2025-01-31 2025-01-31T16:25:40 2025-01-31 5 5 2025-02-28 2025-02-28T16:25:40 2025-02-28 5 6 2025-03-15 2025-03-15T16:25:40 2025-03-15 6 7 null null null null 8 2024-02-29 2024-02-29T16:25:40 2024-02-29 4 Matches the calculation
SELECT dayofweek(shipped)+1 AS result FROM input ORDER BY shipment
shipment shipped received text result 1 2024-12-29 2024-12-29T16:25:40 2024-12-29 1 2 2024-12-30 2024-12-30T16:25:40 2024-12-30 2 3 2025-01-01 2025-01-01T16:25:40 2025-01-01 4 4 2025-01-31 2025-01-31T16:25:40 2025-01-31 6 5 2025-02-28 2025-02-28T16:25:40 2025-02-28 6 6 2025-03-15 2025-03-15T16:25:40 2025-03-15 7 7 null null null null 8 2024-02-29 2024-02-29T16:25:40 2024-02-29 5
Signature
DATEPART(date_part, date, [start_of_week])