Calculated field
ISNULL([amount])
Sample data
| label | quantity | amount | flag |
|---|---|---|---|
| cedar cedar | 65 | 12.8 | True |
| ORCHID-west | 66 | -7.6 | False |
| maple-east | 67 | 0 | null |
| willow north | 68 | 25.3 | True |
| birch-birch | 69 | 4.9 | False |
| pine/south | 70 | -1.2 | null |
| ash | 71 | 9 | True |
| null | null | null | null |
The same calculation as SQL
SELECT amount IS NULL AS result FROM input
Runs the example above.
SELECT amount IS NULL AS result FROM input
Written for this dialect; not run here.
SELECT amount IS NULL AS result FROM input
Written for this dialect; not run here.
Result
| result |
|---|
| False |
| False |
| False |
| False |
| False |
| False |
| False |
| True |
Same rows from the calculation and from the SQL in DuckDB.
Where a naive translation goes wrong
- Replacing ISNULL with amount = NULL changes the shown values or null handling.
Naive SQL
SELECT amount = NULL AS result FROM input
result null null null null null null null null Matches the calculation
SELECT amount IS NULL AS result FROM input
result False False False False False False False True
Signature
ISNULL(expression)