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Failure Count by Mode
How many failures occurred per failure mode? The flags twf/hdf/pwf/osf/rnf are 0/1 in failure_events. Show one row per mode: twf_count, hdf_count, pwf_count, osf_count, rnf_count, total_failures.
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Schema
failure_events
| udi | machine_failure | twf | hdf | pwf | osf | rnf |
|---|---|---|---|---|---|---|
| 5640 | 0 | 0 | 0 | 0 | 0 | 1 |
| 2171 | 0 | 0 | 0 | 0 | 0 | 0 |
| 228 | 0 | 0 | 0 | 0 | 0 | 0 |
Expected output: Failure counts per mode
Hint
SUM(twf), SUM(hdf), etc. SUM of 0/1 columns gives the count.
Concepts
SELECT Aggregation SUM
Practise the topic: SQL practice questions · GROUP BY exercises
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