Calculated field
REGEXP_MATCH([label], 'birch|ash')
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 regexp_matches(label,'birch|ash') AS result FROM input
Runs the example above.
SELECT REGEXP_INSTR(label,'birch|ash') > 0 AS result FROM input
Written for this dialect; not run here.
SELECT REGEXP_CONTAINS(label,r'birch|ash') AS result FROM input
Written for this dialect; not run here.
Result
| result |
|---|
| False |
| False |
| False |
| False |
| True |
| False |
| True |
| null |
Same rows from the calculation and from the SQL in DuckDB.
Where a naive translation goes wrong
- Replacing REGEXP_MATCH with regexp_full_match(label,'birch|ash') changes the shown values or null handling.
Naive SQL
SELECT regexp_full_match(label,'birch|ash') AS result FROM input
result False False False False False False True null Matches the calculation
SELECT regexp_matches(label,'birch|ash') AS result FROM input
result False False False False True False True null
Signature
REGEXP_MATCH(string, constant_pattern)