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WITH yourTable AS (
SELECT '12_23_AB245-F5' AS ColumnA FROM dual UNION ALL
SELECT '66_78_HJ378-G5567' FROM dual UNION ALL
SELECT '55_16_GC761-B99898' FROM dual
)
SELECT ColumnA, REGEXP_SUBSTR(ColumnA, '[0-9]+$') AS last_digits
FROM yourTable;
| COLUMNA | LAST_DIGITS |
|---|---|
| 12_23_AB245-F5 | 5 |
| 66_78_HJ378-G5567 | 5567 |
| 55_16_GC761-B99898 | 99898 |